US police announced last week that they have identified a suspect in the murder of a mother killed in California in 1988.
Last Wednesday, the San Diego Sheriff’s Department announced that it had identified a suspect in a case that was more than 30 years old. Investigator Brian Patterson said advances in DNA testing had tracked down the man who allegedly killed Diane Lynn Dahn in 1988. The 29-year-old mother was found stabbed and beaten to death in her bedroom in her San Diego apartment. It was a colleague who had come to check on her, concerned at not having seen her at work, who discovered the body. Mark, the victim’s two-year-old son, was left at the home and left to his own devices, reports NBC San Diego.
To identify the potential for murder, which had eluded police until then, investigators revisited the case in 2000. That year, they analyzed the victim’s fingernails and entered the results into a database. Ten years later, a hair discovered on one of his hands was tested. Thanks to these years of research, a DNA profile could finally be created and in 2020 investigators began their genealogical work. In recent years, American police have used this technique to solve closed cases. Most of the time she uses publicly accessible websites to find ancestors or their origins. These huge databases make it possible to find relatives of potential suspects or victims. However, it was not specified whether this technique was used in this case.
A neighbor of the victim
In 2022, sheriff’s office teams finally completed their full family tree and identified one Warren Robertson as the prime suspect in this murder. The Arkansas native settled in San Diego before moving to Indiana. He died today after succumbing to a fire. At the time of the murder he lived in the same house as the victim. His name was never mentioned in the investigation and he was never contacted. Authorities said the mother and her alleged killer may have met at El Cajon Speedway, which they both frequented. No motive was mentioned.
Diane Lynn Dahn’s son Mark, now in his 30s, thanked investigators for never abandoning their investigation. During a recorded speech surrounded by his aunt, the victim’s sister, he explained: “It was long. I am so grateful to investigators for everything that has been done over the past few years. I didn’t think we could do anything with it. I had made up my mind that I would be buried without knowing what happened.” The victim’s little sister said: “We used to do a lot together. We went to clubs, we went skiing. It was a wonderful time. We were together all the time. When they told me they finally had results, besides having my kids, it was probably the best day of my life. Now she can rest in peace. At least we have an answer, although that doesn’t lessen our grief.”