When I was in college at U.C. Irvine, my original program of study was for a dual biology and chemistry degree. I switched to mathematics when I realized I had more passion for matrices than molecules. But I’ve always been interested in biochemistry.

An interesting news article caught my attention recently. DNA kinship analysis was used to solve a crime that took place 36 years ago. On November 22, 1984, a 14-year old girl named Wendy Jerome walked out of the door of her home in Rochester, New York after dinner at 7:00 PM to deliver a birthday card to her best friend who lived a few doors down the street.

Wendy’s body was found a few hours later behind a dumpster. She had been raped and then brutally beaten to death.

DNA matching did not exist in 1984. The first use of DNA matching in a criminal case occurred in 1986. But Rochester police saved Wendy’s clothes. Years later, DNA matching had become a common technique, but the unknown murderer’s DNA on Wendy’s clothes did not match any criminal in the CODIS database.

Left: Wendy Jerome. Right: The murderer, Timothy Williams from a police booking photo (with watermarks).

However, a recently developed technique, DNA kinship analysis, solved the crime in September 2020. Technicians analyzed the unknown murderer’s DNA and generated a list of criminals whose DNA was in CODIS and who were highly likely to be related to the murderer. This list quickly identified a suspect, Timothy Williams. Williams’ DNA was obtained, and it matched the DNA found on Wendy Jerome 36 years before, proving he was responsible for the crime. Williams is age 56 now so he was 20 years old when he raped and murdered Wendy Jerome.

The first DNA matching techniques, which were developed in the 1980s, are based on classical statistics, leading to statements like, “There is only one chance in 100 trillion that the DNA came from someone other than the suspect.” However, deep neural machine learning techniques are now being applied to DNA analysis, including kinship analysis.

Fascinating. Kinship analysis is part of a larger field of study called bioinformatics. I wish I knew more about bioinformatics, especially new techniques that use deep neural technologies. But with the Internet, I’m quite sure I’ll learn as time goes by.

This story illustrates incredible science — the best of humanity — and an evil person that represents the worst. It’s a good thing to bring criminals to justice, but I hope that some day machine learning and AI can be used to prevent crime before it happens.