A test in which complex DNA profiles are intensively compared with the DNA database has identified new suspects in at least fifty serious criminal cases in two years. That reports the Netherlands Forensic Institute (NFI) Friday. Due to the success, the NFI will now use the new working method as standard.
Every year, detectives find five hundred to six hundred DNA profiles that are incomplete or contain DNA from several people. In the trial, the NFI compared complex DNA profiles of this kind with the DNA database every two months using new software. That software can perform more complex DNA analyzes than before and automate the execution of analyses. In the past, the NFI usually only compared complex profiles once with the DNA database in order to trace suspects. Sometimes this was done again, but only at the specific request of the police or the Public Prosecution Service.
In the past, detectives sometimes decided to analyze a certain complex DNA profile again later, but there were no clear agreements about this yet. “Some detectives did this in a very disciplined way in a self-created Excel file, others did it less structurally in a notepad, and still others did not keep such lists at all,” says Thalassa Valkenburg, forensic adviser to the police. “It was every man for himself. (…) And when someone left the service, his or her list often disappeared too. We missed a lot of opportunities that way.” The DNA database grows by more than 20,000 profiles every year, which makes it useful to conduct repeated research.
Automatically
With the new software, the police are automatically asked whether a DNA profile is eligible for repeated analysis. The fifty matches that emerged during the trial are linked to shootings, violent incidents, drug offenses and kidnappings, among other things. “Things that would probably not have been solved otherwise,” says Valkenburg. The ‘New Round of New Opportunities’ trial was carried out by the police, the Public Prosecution Service and the NFI.
DNA comparisons can be decisive in forensics. “When there is a DNA agreement, the other evidence is often not even mentioned in many judgments,” says forensic prosecutor Mirjam Warnaar.