DNA analysis
Forensic method deriving DNA profiles from biological traces as criminal evidence
DNA analysis is a forensic genetic method in which biological material — such as blood, saliva, hair or skin cells — is examined in order to derive an individual DNA profile that can be used as evidence or as an investigative tool in a criminal case. The method is a central element of modern criminal investigation and is used systematically by Danish police and prosecutors.
In a criminal law context, the purpose of a DNA analysis is typically threefold: to link a specific person to a crime scene, to exclude suspects from an investigation, or to identify an unknown person — whether a perpetrator, a witness or a victim. In cases involving serious crime, including homicide and violence, DNA traces often constitute one of the weightiest forms of evidence.
When biological traces are collected at a crime scene, the material is sent for forensic genetic analysis, where a DNA profile is derived. This profile can then be compared with profiles in the Central DNA Profile Register, which contains registered profiles from previously convicted and charged persons, and with traces from other cases. A match — or the absence of one — can be decisive for the direction of the investigation and for the presentation of evidence in court.
In articles about specific crimes, such as homicides on motorways or in other public places, the term DNA analysis typically refers to the phase of the investigation in which police seek to identify the perpetrator or confirm a suspect's presence through biological traces found on the victim, on vehicles or at the scene. The analyses are carried out by specialised forensic genetic laboratories.
Under Danish law, the use and registration of DNA profiles is governed by the Act on the Central DNA Profile Register and the Central Fingerprint Register (lov om Det Centrale DNA-profilregister og Det Centrale Fingeraftryksregister) and by the Danish Administration of Justice Act (retsplejeloven), which sets out the conditions under which police may obtain biological material from a charged person, and how profiles may be used and stored.
