Use of DNA in criminal investigations
The National DNA Data Bank (NDDB) helps support the law enforcement and the criminal justice communities. It is a national system that compares DNA profiles from across the country. The database and highly specialized services saves the criminal justice system time and resources in support of public safety.
When police investigate a crime scene, they collect biological evidence. They send this evidence to a public forensic laboratory for DNA analysis.
Once the laboratory analyzes the evidence and generates DNA profiles, the laboratory can upload the "suspect" DNA profile(s) from the crime scene into the NDDB Crime Scene Index. Only approved laboratories can upload these profiles into the NDDB.
The NDDB then compares the crime scene DNA profile against profiles contained in other criminal and humanitarian DNA indices as permitted by the DNA Identification Act. One of the goals is to determine if there is a match to the profile of a known convicted offender so the name of a potential suspect can be released to the investigator.
The crime scene DNA profile remains available for comparison against new profiles entered in the future.
The NDDB can also help link crime scenes between different police jurisdictions. Investigators can then contact each other and possibly come up with a common suspect. This helps investigators identify serial offenders who operate in different locations.
Convicted offenders submissions
The NDDB receives, assesses and processes all convicted offender submissions.
Based on whether the offender's DNA profile is already contained in the Convicted Offenders Index, there are two types of submissions that are sent to the NDDB:
- a full biological sample submission, which contains documentation, fingerprints and a biological sample collected from a convicted offender
- an endorsement submission, which contains documentation and fingerprints only. See endorsement instructions under Forms for more information.
A data bank analyst processes the biological sample to generate a DNA profile of the offender. They then enter the profile into the Convicted Offenders Index.
DNA indices used in criminal investigations
- Convicted Offenders Index
- Contains DNA profiles from offenders that have been convicted of designated offences as identified in section 487.04 of the Criminal Code
- These profiles can be compared to DNA profiles in the Crime Scene Index, the Victims Index, the Voluntary Donors Index, the Missing Persons Index and the Human Remains Index
- Crime Scene Index
- Contains DNA profiles from crime scene investigations of designated offences
- These profiles can be compared to DNA profiles in the Convicted Offenders Index, the Crime Scene Index, the Victims Index, the Voluntary Donors Index, the Missing Persons Index and Human Remains Index
- Victims Index
- Contains DNA profiles from victims of designated offences
- These profiles can be compared to DNA profiles in the Convicted Offenders Index, the Crime Scene Index, the Voluntary Donors Index, the Missing Persons Index and the Human Remains Index
- Voluntary Donors Index
- Contains DNA profiles from voluntary donors associated with the investigation of a designated offence or a humanitarian investigation
- These profiles can be compared to DNA profiles in the Convicted Offenders Index, the Crime Scene Index, the Victims Index, the Missing Persons Index and the Human Remains Index
Victims and voluntary donor submission information
Please visit the National DNA Data Bank Forms page for submission information and for the Guide to the Victims Index and Voluntary Donors Index.
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