Offences investigated

An offence is considered completely investigated at the time a decision with legal efficacy has been made regarding the offence.

1) Offences are in the crime statistics defined as the actions, which by law are described as punishable at any given time. The investigated offences are separated by type of offences, police district and by police decision. Cases reported to and investigated and completed by the Norwegian Bureau for the Investigation of Police Affairs are not included in the data basis for the statistics on offences investigated (see Coherence with other statistics under Background). Violations under the Road Traffic Act or Customs Act that are settled by on the spot fines are not regarded as offences reported to the police, and are not investigated by the police and Prosecution authority. They are therefore not included in the statistics (see statistics on Sanctions).

2) Charges

3) Charged persons

More detailed description of units and variables:Offences in the crime statistics are the acts which at any current time are considered to be unlawful in the penal code. To date, more than 1 260 different codes have been used in BL/STRASAK/PAL, of which about 660 different codes are actively used today to classify offences. Following the Penal Code of 2005 coming into effect on 1 October 2015, around 430 new codes were introduced into the police’ central registration system for offences. These replaced the codes from the Penal Code of 1902, which are about the same in numbers. Consequentially, Statistics Norway now use the new version of Standard for types of offences, Type of offence 2015, to classify offences. From the release of the year 2015 and onwards, the statistics thus contain the following groupings of offences (see also Statistical Classifications and Code Lists – Klass):

Group of offence, where offences are divided into nine main groups. These groups of offences are further divided into more specified types of offences (see Type of offences).

Type of offence, where offences are divided into about 150 unique types of offences. Similar types of offences are grouped together to a varying degree of aggregated levels, where all levels are included in the nine groups of offences.

Category of offence was a classification of offences used in the statistics for the period 1993-2014, where offences were classified as either a crime or a misdemeanor. For more information on this expired classification, see the version Types of offences 2006 in Klass and About the statistics 2014 for Offences investigated.

A decision with legal efficacy can be given by the police and the prosecuting authority, or by the courts. The legal decision implies that the police and prosecuting authority or courts consider the offence as completely investigated - and that further investigation is not of current interest (unless retrial at a later time). The basic material contains about 200 different types of legal decisions. How offences are settled by the police and prosecuting authorities, are described by the statistics on investigated offences. (Other registers than STRASAK are used for statistics on sanctions). All court decisions, e.g. unconditional imprisonment or acquittal, are for this reason classified as decided by prosecution in the statistics on investigated offences. Some decisions made by the police and the prosecuting authority, conclude that no offence has been committed. Cases with such decisions are not considered as offences and so not included in the statistics on investigated offences.

Persons charged are, by Statistics Norway's definition, persons who have a legal decision against them. Common to all "persons charged" is that they are regarded by the police and prosecuting authorities as perpetrators, and have had the status as charged at the completion of the investigation (prior to any prosecution and court trial).

A person suspected of having committed offences can get a legal status as charged at various times during the investigation of a criminal case (e.g. the status of prisoner in custody is person charged). Charges can, however, be withdrawn during the investigation so that by the completion of the investigation the person is no longer regarded as charged. In other words, persons who have been charged during the investigation, but not at the completion of the investigation, are not included in the statistics. Because the statistics do not cover everyone who has had the status of being charged, Statistics Norway's use of the term "charged" is not synonymous with corresponding terms in Section 82 of the Criminal Procedure Act. All "persons charged" in the statistics have, however, have had the status of charged in connection with the offences for which they have received a legal decision.

In some cases a person may be a participant in several offences and thus incur several charges in the course of the statistical year. The tables of persons charged show the number of different persons who have been charged in the course of the statistical year. In other words, a person is counted only once as charged in the course of statistical year. In other cases several persons may have participated in one individual offence, i.e. several persons may be charged with the same offence. In such cases, all these persons are included in the tables of persons charged. On the basis of these two factors, the number of persons charged will be different from the number of offences solved by charge.

Principal offence : A person, who has been charged with several offences in the course of the statistical year, will be grouped by the principal offence in the tables, i.e. by the offence, which by law carries the longest sentences.

The percentage of solved offences is calculated from Statistics Norway's classification of the legal decisions. As a main rule, all offences in which the police and prosecuting authority have charged at least one person at the completion of the investigation count as solved. The offence also counts as solved when prosecution is dropped or withdrawn, but in such cases no information is obtained on possible persons charged. The percentage is calculated from the number of offences solved by the police and prosecuting authority. This implies that all offences transferred to (with prosecution or charge in the magistrate's court) and decided in the courts, count as solved. This also applies to the offences in which the court at a later time has acquitted the putative perpetrators for the offences for which they have been charged. Cases in which the investigation has concluded that an offence has not taken place are not included in the statistics on investigated offences, or in the calculation of the percentage of solved offences. The percentage solved for various types of offences varies widely. An overall percentage of solved offences for the entire country, or for a police district, is therefore highly dependent on how the offences are distributed by type.

Recidivism : An ongoing survey of recidivism among persons charged at the completion of the investigation is carried out. The survey covers persons charged with crimes during the year five years ahead of the statistical year. Recidivism here is defined as a new charge in one or more of the following five years. The survey does not take into account various forms of recidivism obstacles during the observation period. Persons charged with uncertain information about identity and/or time of a crime, are not in the survey.

Police districts are used to break down violations of the law according to the body that is ascribed as owner of the criminal proceedings, on the date Statistics Norway takes an extraction of the basic data.

From 1 January 2016, Norwegian police were organised into new regional districts, where 27 police districts were reduced to 12. Statistics Norway release figures by this new division from the year 2016 and onwards, even though the data basis for the production of the statistics does not contain criminal case data with allocations by the new district standard, and that the internal process of organising the new district will be executed over the course of 2017 and 2018.The new police districts are mainly organised by a merger of former districts, which at an aggregated level are comparable to the previous organisation of 27 districts. The exemption from this is the former police district of Midtre Hålogaland, which after the new organisation is divided by the county border between new Nordland PD and Troms PD. However, derived from information about owner district by the previous organisation, as well as information about the criminal cases belonging in terms of police branches and scene of crime, Statistics Norway have been able to allocate all criminal cases after the new organisation of police districts. All offences with a branch code for the police stations in Harstad, Iberstad and Salangen have been ascribed to Troms PD as the owner district. Furthermore, offences with a scene of crime in Troms County and with branch codes for Evenes, Tjelsund and Skånland police station, as well as "Joint Operational Unit" (Fellesoperativ enhet) and "Eco Team" (Økoteam), have been ascribed to Troms PD as the owner district. Remaining offences registered with the former Midtre Hålogaland PD as the owner district have been ascribed to Nordland PD. For a complete overview of Police Districts 2016 and previous organisations, including relation to municipalities, see Statistical Classifications and Code Lists.

In addition to the 12 geografic police districts (see Standard classifications), the Governor of Svalbard and some central Special agencies can also be owners (i.e. have responsibility for follow-up) of criminal cases during different stages of the criminal proceedings process. The Norwegian National Authority for Investigation and Prosecution of Economic and Environmental Crime (Økokrim) and The National Criminal Investigation Service (Kripos) have prosecuting authority and can decide criminal cases, and are therefore included in the category Special agency.

Age is defined as a person’s wholly lived years at the time of the offence.

Sex is defined based on two different sources. Where there is a match for personal ID numbers in the Central Population Register, the person`s sex is derived from this source. For all persons who cannot be identified in the Central Population Register (by means of date of birth, personal ID number or name), information about sex registered by the police is used.

Group of offence (9 main groups). See Standard for type of offences 2015 in Klass.

Type of offence. See Standard for type of offences 2015 in Klass.

Police district (see Definitions of the main concepts and variables. Up to 31.12.2001: 54 police districts plus special agencies. From 01.01.2002 included: 27 police districts plus special agencies. From 2016: 12 police Districts plus special agencies)

Citizenship and continent:

Age (Up to 1999 included: groups 5-13, 14-17, 18-20, 21-24, 25-29, 30-39, 40-59, 60-. From 2000 included: groups 5-14, 15-17, 18-20, 21-24, 25-29, 30-39, 40-59, 60-.)

Sex

Name: Offences investigated
Topic: Social conditions, welfare and crime

Division for Income and social welfare statistics

National, county and police district level.

Annual. Normally published in the third quarter of the year subsequent to the statistical year.

Because of changes and other circumstances, the statistics have been published later and with irregular intervals in some of the previous years.

Reporting some statistics to the Eurostat and UN .

Raw data files of whole-year files from the Police Computing Service are stored electronically. Volume files with completely processed material are stored electronically (volumes from 1987 have been adapted to the new technological platform).

The statistics describe how the police and prosecuting authority settle offences when investigation is completed, percentage of solved offences, alleged offenders when investigation is completed (persons charged) and recidivism among these. The statistics on completely investigated offences has been published annually from 1957 included.

The statistics is used to describe the registered crimes and their offenders from 1960 up to 1991, and the registered offences from 1992 and up to today. The principle division between crimes and misdemeanours has been discontinued in new Penal Code of 2005.Separate statistics on Offences reported to the police exists from 1993 and are used for this purpose if trends are to be described from this time).

After a gradual transition from reporting through forms to reporting electronically (completed in the years around 1990), the central police registration system (STRASAK) has been the basis for the stistics. In 2002 there was made changes in the processing in accordance with new structure for the police districts and the subsequent alteration in the police's registration systems (BL/STRASAK/PAL).

Major users are the media, research and education sector, interest organizations, the Ministry of Justice and the Police, and other public services and institutions associated with the justice sector. Beyond this the statistics serve as the basis for information for others interested in the status of and trends in crime.

No external users have access to the statistics and analyses before they are published and accessible simultaneously for all users on ssb.no at 8 am. Prior to this, a notice is given in the Statistics Release Calendar. This is one of the most important Principles for Equal treatment of users in releasing statistics and analyses.

The statistics over investigated offences one of four main crime statistics in the area of Crime and the justice . The others are Offences reported to the police , Sanctions , and Imprisonments .

In general the offences included in the statistics offences reported shall same or later years be represented in the statistics over investigated offences, sanctions and imprisonments (see separate statistics for Criminal prosecutions, in Norwegian only ). When using the crime statistics it is, however, important to be aware that the various parts do not necessarily refer to the same population of offences within the same statistical volume. It can take a long time from an offence is reported until it is investigated and possibly sanctioned, in some cases years. The units counted ar also dissimilar in the different statistics, although offences are counted quite similar for reported and investigated offences. The tables on offences reported to the police are therefore not comparable with the other crime statistics.

Other closely related statistics at Statistics Norway are: the Survey of level of living, victims and crime (exposure to violence and theft), Victims of offences reported to the police , Police and prosecution - StatRes (discontinued) and Causes of death (murder) (discontinued).

Of related external statistics, the Police directorate (POD) also publish figures on percentage of offences solved and time of dealing with cases, based on investigated offences in STRASAK/PAL, but these are to be considered as operation statistics for the police, and should not be read as the official crime statistics. These statistics are also defined and produced on other criteria and with other groupings than Statistics Norway, and do not have directly comparable figures.

The Norwegian Bureau for the Investigation of Police Affairs investigates cases where employees of the police or prosecuting authority are suspected of committing criminal offences in the course of duty. Offences which are investigated and completed by the Bureau without further prosecution or court proceedings are not included in the data basis for the statistics on offences reported to the police and offences investigated. However, when such cases result in a sanction registered in the Criminal Record Register, they will be included in the statistics on sanctions. Furthermore, such cases are included in the statistics on imprisonments in the same manner as other criminal cases.

The Bureau is an independent body, and is not organised as part of the police. The Bureau is administratively under the Ministry of Justice and Public Security, and professionally under the Director of Public Prosecutions (which also functions as the body of appeal for cases where prosecution is dropped and other types of prosecution decisions made by the Bureau). In their annual reports, the Bureau publishes statistics on offences reported and investigated over the course of the year.

The Norwegian National Criminal Investigation Services (Kripos) also publishes figures on homicides, but these statistics are counted from another definition of the selection than SSB's statistics over investigated offences (among other things the year of action, not the year of decision with legal efficacy).

Statistics Act §§ 2-1, 2-2, 3-2 (forms/registers).

The statistics cover all offences completely investigated within the statistical year. The statistics provide information about the type and number of offences, police district, scene of crime, the police decision, and the persons charged at completed investigation. It provides information about the age, sex, citizenship and place of residence, and recidivism of the persons charged. (see descriptions of concepts and variables in Definitions, and estimations in Collection of data revision and estimations).

Violations against the Road Traffic Act and Duty Act in which the sanction is imposed as a on the spot fine, are not covered by the statistics (see instead statistics on Sanctions). Cases reported to and investigated and completed by the Norwegian Bureau for the Investigation of Police Affairs are not included in the data basis for the statistics on offences investigated (see Coherence with other statistics under Background).

From 1992 to 2014 the statistics contained both crimes and misdemeanours. For previous years, the statistics is only for offences. The principle division between crimes and misdemeanours has been discontinued in new Penal Code of 2005. The definisions of the population – criminal cases, offences investigated and the offenders are equal before and after this change in 2015 (see under Defintions ans Sources of error and uncertainty).

Each offence with a legal decision makes one unit in the basic material. Before 1994/1995 the practice was that several offences could be registered as one (see Comparability over time and space).

From 1991 the data source is completely EDP based and drawn from the central police registration system, STRASAK, which covers all completed investigations of offences recorded by Norway's police districts (BL), as well as special agencies and higher prosecution authorities, as part of the processing of the criminal case. From 2002 the selection is decided in STRASAK, but the actual data extension are done through the police' analysis and management tool (PAL).

The various police districts are, via Kripos, asked to provide information in the cases where Statistics Norway finds logical errors and missing information in the data material. The statistical process includes information from the national register (see Population statistics), and previous volumes of statistics on investigated offences.

Not based on random sample but a complete selection, the statistics shall contain all offences and persons charged in criminal cases the police and prosecuting authority has registered as completely investigated during the year. The Norwegian Bureau for the Investigation of Police Affairs investigates cases where employees of the police or prosecuting authority are suspected of committing criminal offences in the course of duty. The Bureau registers cases in a separate registry version of BL/STRASAK/PAL, and these cases are not included in the data basis for the statistics on offences investigated (see Coherence with other statistics under Background). See also Population, Collection of data editering and estimations, Confidentiality and Comparability over time and space. The selection is also described in more detail, see Definitions of the main concepts and variables under Definitions.

The data files are collected in digital form from Norwegian Police ICT Services (previously The Norwegian Police Data Processing Service (PDMT)) mid January. Norwegian Police ICT Services runs out the data from STRASAK/PAL. The register is centrally completely updated the day (longer before) after local registration in BL (this is less relevant than earlier). With that, Statistics Norway can obtain information about two weeks days after the end of the statistical period. Information on incorrect entries and missing data is obtained from Kripos (from the statistical year 2015, and in previous years the police Districts and from Police ICT Services) in the course of the first and second quarter of the year though error tables. Information related to persons is electronically connected from SSB's population register.

The register systems of the police contain some validity controls of data. In addition, Statistics Norway undertakes controls and editering of the material. For example will deficient information on scene of crime by municipality, be added municipality to the extent possible out of other information from the register.

An overview of all controls and Statistics Norway's processing routines are found in "Statistikk over etterforskede lovbrudd. Dokumentasjon", Notater 1999/52, StatisticsNorway. Validity controls in STRASAK/PAL and Statistics Norway's processing routines are redeveloped as needed, resulting in constant improvement of the data material (see Comparability over time and space for new routines from 2002).

Figures are not based on estimations, as the three basic units consists of complete counts of the data from the police registers (for an account of concepts, see Definitions of the main concepts and variables under Definitions):

• All offences completely investigated are counted, with given characteristics (e.g. type of offence, police district and police decision). From these numbers the percentage of offences solved are calculated, in total and for each type and group of offence.
• All unique charged person are counted, and the number of these with given characteristics (e.g. sex and age). For persons with more than one offence during the year the principal offence are applied by the use of an indicator of graveness based on maximum and minimum sentence beside other characteristics of the criminal procedure.
• Recidivism is counted as charges during the last five statistical years against persons (with full personal identification number) charged in the statistical year prior to these five.

Calculations in per cent and per 1 000 inhabitants (5 year and up) are being made by use of number of inhabitants 31'st of December in the statistical year (also for each age group, sex, and geographical area - see Population statistics ). As a general rule, all figures for charged persons per 1 000 population (both total and the whole country) are calculated from the population aged 5 years and over. This is because of the statistical definition of charged persons, with 5 year olds as a starting point. When figures per 1 000 population are calculated for the variable offence, however, the population is used as a whole – as it is done for example for the statistics on Offences reported to the police.

The statistics implies particularly sensitive personal information and information on punishable offences considered as extremely sensitive. Statistics Norway administers the data basis for crime statistics with great caution. When releasing statistics showing few units, the protection of privacy is considered on each incident.

There are many conditions that can be significant for the comparability over time of the different crime statistics, and is not described in a broad manner here. But a few central changes during the last decades can be pointed out:

Introduction of Strasak ca. 1985-1990
Before the 1980s individual forms with data on the crime cases were obtained from police districts and recorded by Statistics Norway. Oslo switched to edp based registration in 1979, followed by the police districts in Agder in 1981. STRASAK was introduced at the various police departments in subsequent years, and by the end of 1991 all districts had switched to electronic registration. A while after STRASAK was introduced at the various police districts, reporting to Statistics Norway was done electronically.

A reorganisation in 1984 entailed that STRASAK cover crimes finally given a legal decision during the statistical year (not completely investigated before a possible trial, as was previously the case). The previous selection criteria were, however, maintained for the police districts that did not report with STRASAK after 1984 (see Sources of error and uncertainty under Sources of error). When departments switched to reporting with STRASAK the selection criteria were changed. Because the selection criteria were different for the various departments, and were changed in conjunction with the transition to electronic reporting by the individual districts, some crimes were counted twice in the period from 1984 up to 1991/1992. The extent of the double registration caused by these transitions is uncertain. Probably there were not many double registrations, but it may have happened with certain serious crime cases where a charge was handed down at the end of the year in question.

New registration practice 1994/1995
Each offence with a legal decision makes one unit in the basic material. This has been the practice since 1994/1995. Before this, only one offence was registered when:

• Several offences were committed in one act against one victim. The most serious offence was registered.
• The same person committed several homogeneous offences over a period of time against one victim.
• One offence was committed as a path-breaker for the other offence.

More offences were, however, registered when an offence was committed to hide another offence, just as the practice since 1994/1995.

STRASAK has been under development for a long time regarding to quality assurance and registration of details. Because of this development the data source of the statistics contains more information than before. The changeover in 1994/1995 to registering all offences is of great importance, and caused an increase in the number of investigated offences in the statistics without there necessarily being more offences investigated.

Reorganisation of Strasak in 2002
As of 1 January 2002, a new structure for the police districts was established; where for one thing the number of police districts was halved. Statistics Norway has as result of this, and the following technical re-adjustments in the central police criminal register system (BL/STRASAK/PAL, from October 2002 included), changed the routines for producing the statistics on offences investigated. News on statistics on offences investigated from 2002 included:

• New police districts replace the previous geographical division. The possibilities of comparing these to statistics on police districts prior to 1 January 2002 are to a great extent restricted.
• Several persons charged without registered and valid official Norwegian reference number are being identified if they have committed more than one offence. This gives a somewhat lower number of persons charged and a higher number of persons charged with more than one offence, for persons committing offences when on a temporarily residence in Norway in particular.
• Statistics on the number of accessories shows to a greater extent the actual number of offenders with who the person charged has committed the offence in cooperation with. This involves a somewhat higher number of accessories than it would have been out of the previous method of surveying these.
• Transfers to Conflict Council are only made available as settlement valid in law only against persons charged over the age of consent. This involves that the number of transfers to Conflict Council decreases, and that prosecutions dropped, the offender not liable, become correspondingly more.

After a thorough examination of the different data basis and crime statistics, in addition to dialogue with Norwegian Police ICT Services, Statistics Norway is of the opinion that the statistics on offences investigated from 2002 and following, has become fairly comparable to previous years. The police reform, together with the changes made in Statistics Norway's own categories is however of some importance to comparability of the statistics over longer time.

Introduction of the new penal code on 1 October 2015: After the new penal code (Penal Code of 2005) came into effect on 1 October 2015, the raw data from the police registers are changed. There are quite distinct differences in structure, language and content between the Penal Code of 1902 and the Penal Code of 2005, which is even more evident in the corresponding codes used for registering offences in the police’ central registration system. Code connected to both the new and the former penal code is used after 1 October 2015, due to the new legislation not having retroactive effect. Offences may be registered and processed long after they have been committed. This means that the Penal Code of 1902 and 2005 will appear in the data of all crime statistics for many years to come.

Criminal cases with violations of the provisions dating before the introduction of the new penal code (registered by former codes and appellation), will not always be possible to specify and classify in the same way as criminal cases with a violation of a corresponding provision from the Penal Code of 2005. Certain types of offences in Standard for types of offences 2015 will therefore exclusively contain violations of offences stemming from new penal legislation, and mainly consist of offences committed after 1 October 2015. In the standard, these will be indicated with “(from 1.10.2015)” in the classification name. Older offences which cannot be specified in the same way are placed in “other or unspecified” types of offences. The content of the statistics – and the possibilities of doing comparisons on the most detailed levels of the standard – will for certain types of offences therefore be mainly based on offences committed after 1.10.2015. This type of break in the time series will vary over time for the different types of offences, depending on which crime statistics you use. When such breaks in the time series are identified, the general recommendation is to use figures on a more aggregated level, which means less specified figures with a smaller degree of time series break. Se Standard for type of offences 2015 in Klass and the article "The New Crime Statistics" (in Norwegian only).

Other changes
Also other changes have been made, contributing to higher quality of the statistics, and influencing the comparability over time.

National Authority for Investigation and Prosecution of Economic and Environmental Crime inNorway(Økokrim) have been included in the statistic since 1995. After The National Criminal Investigation Service (Kripos) also was given prosecuting authority in 2005, the police district category "Special agencies" have been specified in tables, which includes both agencies.

On 1 January 2016, Norwegian police were organised into new regional districts, where 27 police districts were reduced to 12. The internal process of organising the new districts will be executed gradually during the course of 2017 and 2018, but as of year 2016, Statistics Norway will only release statistics by the new police districts in StatBank. The new police districts are mainly organised by merging the former districts, which on an aggregated level are comparable to the former division of 27 districts. However, in the new organisation, the former Midtre Hålogaland PD is divided by the county border between new Nordland PD and Troms PD. Thus, comparisons across the new and former district are not possible for the districts in question. For a detailed overview of the new police districts, including their relation to municipalities, see Statistical Classifications and Code Lists.

From 1 January 2020, there have been major changes in the division of counties and municipalities, due to regional reform. The changes are described in this article (only in Norwegian). This also means that the police districts, which in turn consists of a whole number of municipalities, have changed. See Classification of county, Classification of municipalities and Classification of Police district.

The principal offence is defined as the offence, which by law carries the longest sentence. Many offences have a broad sentencing framework. Because only the general provisions of the law are taken into account and not the individual differences in the seriousness of the offences, this method could cause the charged person to be grouped under another offence than the most serious one in the specific case. Because three-fourths of the persons charged are charged with only one offence, and the others have a tendency to be arrested for the same type of offence, a relatively limited number of persons charged are classified under another offence than the most serious one.

Offences, in which the police complete the investigation by recommending prosecution, are not included in STRASAK until a legal decision is made. Consequently, it is the offences tried in the courts that come under the "Committed for trial" decision category (see Definitions of the main concepts and variables under Definitions and earlier sections on the transition to a new criterion for selections introduced with STRASAK in the time period from 1984 to 1991).

In the case of offences involving several perpetrators, the police decision can be different for the various persons charged. Tables, in which the offences are grouped by type of decision, show only the decision for one casual chosen of the persons charged (of all offences completely investigated in 2015, 2 per cent involved more than one person charged).

The decision "Transferred to Conflict Council" means that the offence reported to the police and the person charged have been transferred to a conflict council -and that the police and the prosecuting authority have been informed that the council has arrived at a solution. The offences that were transferred but not solved through mediation in the conflict council will get other legal decisions categorized under other types of decisions in the statistics.

The vast majority of offences have only one point of time at which the offence was committed, but for the offences that have taken place over a period of time the age is set according to age at the time of the first offence. In addition, the age of the person charged would always be set according to his or her age at the time of the most serious offence that the person is charged with in the course of the year. In some cases this causes the age of the person charged to be somewhat misleading: Persons under the age of consent (15) may appear in the statistics as charged and punished. The fact that persons under the age of 15 appear as charged or punished, however, are due to incorrect registration by the police or that the wrong decision was made by the prosecuting authority or court.

Based on experience, incorrect registration is often the reason why persons under the age of 5 are registered as charged. Therefore personal information about persons charged under the age of 5 is removed from the statistics (and the population aged 5 years and up is used to calculate persons charged per 1 000 inhabitants).

An offence can be included as part of the investigation of a complex of cases. This can be the case when a person is investigated for several homogeneous offences against various victims, or when many persons are investigated for one or more offences that have taken place in the same situation. An offence, and the legal decision made, will not be included in the statistics before all of the remaining offences in the complex of cases are legally decided. This entails that some offences are legally decided before the year the offence becomes part of the statistics (in the statistics for 2015, under 6 per cent of offences were decided in a year prior to 2015).

Attempted offences are in most cases punishable. Attempted offences are usually registered as committed offences in the basic material of the statistics. Surveys indicate that the rule previously was followed only exceptionally concerning murder, and that attempted murder up to 1987 was usually recorded as grievous bodily harm. After the introduction and development of STRASAK, attempts at certain types of offences, e.g. attempted murder and attempted rape, have been registered and presented as separate types of offences in the statistics.

Offences dismissed by the police are in the statistics regarded as completely investigated. If such a dismissed offence is solved in a subsequent year, it will count both the year it was dropped and the year it was solved.

Processing of the data at Statistics Norway show that the various police districts make some obviously incorrect entries. Every year there are some cases were corrections are not returned to Statistics Norway. Information from the police districts that make corrections will be more complementing and correct than information from the police departments that do not return corrected lists.

BL/STRASAK contains a large selection of various categories for registering offences and legal decisions (see Definitions of the main concepts and variables under Definitions). As long as valid codes for offences and legal decisions are used, Statistics Norway cannot, by processing the statistics, discover whether the right categories are used. Partial non-response (in that certain variables are not given for some units) occurs, but with the aid of internal controls in STRASAK these are limited to less important variables.

The greatest possibility that incorrect categorization may have occurred in registering offences, is in the statistics on offences reported to the police , and then in particular the more specialized types of offences. Registration of type of offence and legal decision at the end of the investigation are made on a lawyer's evaluation, and therefore considered being more reliable than the registration done at the time of reporting to the police.

See Data sources and sampling under Production.

The crime statistics cover only registered crime, i.e. offences that the police discover or get knowledge of. Police resources and priorities and the tendency of people to report offences to the police, are of great importance to which acts become part of the crime statistics. An unknown number of offences are never registered. Such unregistered offences are usually called missing figures. Various interview surveys on self-reported crime and susceptibility to crime, indicate that unregistered crime is extensive (see Survey of level of living, victims and crime , Statistics Norway). What is registered of crime over time is necessarily also influenced by changes i laws and regulation (see Comparability over time and space under Production). These phenomenons are nonetheless not actual statistical "errors”, but elements that influences it.