Recent advances in forensic science, including a powerful computer program able to reconstruct degraded DNA, allowed law enforcement officials in Utah to close a 52-year-old cold case and attribute the 1974 murder of a teenage girl to Ted Bundy. Scientists at the Utah Bureau of Forensic Services linked Mr. Bundy to the 1974 murder of Melissa Ann Smith. It was the second decades-old murder in the state attributed to Mr. Bundy this year.
In April, investigators determined that he had also murdered Laura Ann Aime. Both were 17. The body of Ms. Smith was found a few weeks before that of Ms. Aime.
Now, their cases have been solved months apart, after the DNA found at one crime scene became instrumental in solving the other’s murder. A key connection between the victims was made using STR genotyping and an innovative software known as STRmix. Forensic scientists were able to connect the cases to each other and Mr. Bundy using these tools.
The software uses modeling to untangle genetic profiles and gives a statistical readout about the likelihood of a match. After identifying a likely DNA profile through STRmix, investigators ran it through the CODIS database. There was a match.
The results left little doubt that the DNA found on Ms. Aime belonged to Mr. Bundy. The case of Ms. Smith presented a different challenge. Investigators had Y-STR evidence, which meant they knew it came from a male, but determining its origin would be more difficult.
Y-STR testing can be really valuable to target in on male-specific DNA, especially when dealing with low-level or degraded samples.
Source: New York Times Top Stories · Summarized by HeadlinesBriefing