The Copenhagen Police in Denmark have made a significant advancement in solving a murder case that has remained open for 34 years. Authorities recently arrested a 53-year-old man, who has been charged with the 1990 New Year’s night murder of Hanne With.

The breakthrough in the case was achieved using familial DNA searching. This method involves analysing DNA material found at the crime scene (in this instance, on the victim’s trousers) and comparing it to DNA profiles in a police database to identify potential relatives of the suspect. This strategy led investigators to the 53-year-old suspect who is now in custody.

Mikkel Meyer Andersen, a lecturer at the Department of Mathematical Sciences at Aalborg University, highlighted the importance of this method. Andersen, who has extensive experience in mathematical and statistical evaluations of DNA evidence and has served as an expert witness in murder cases, remarked, “This case showcases the significant potential of DNA familial searching as an effective investigative tool. To my knowledge, this is the first instance of Danish police using familial searching within the DNA database to identify potential culprits.”

He further stressed the utility of DNA familial searching in reopening and potentially solving cold cases, noting its ability to pinpoint suspects in cases that might otherwise remain unresolved. However, Andersen also cautioned that while DNA evidence is pivotal in identifying suspects, it does not guarantee a conviction, emphasising the necessity for additional evidence to substantiate charges against the suspect.