DNA from cigarette identifies teenage girl’s killer — 44 years later

A jury found James Unick, 64, guilty of killing Geer on February 13, which would have been her 57th birthday

Sarah Geer, 13, was last seen leaving a friend’s home in Cloverdale, in the San Francisco Bay Area, on May 23, 1982 (Sonoma County District Attorney's Office )

More than 40 years after a teenager was brutally murdered in California, authorities used DNA found on a discarded cigarette butt to catch her killer.

Sarah Geer, 13, was last seen leaving a friend’s home in the town of Cloverdale on May 23, 1982.

As she walked downtown, she was approached by James Unick, who forcibly dragged the teen down an alley, where she was “brutally raped” and strangled to death with her own shorts, the Sonoma County District Attorney’s Office said.

The teen’s body was discovered the following morning by a Cloverdale firefighter who was walking home after his shift. While her death was ruled a homicide, “limited forensic science of the day” kept the case cold for decades, prosecutors said.

A jury found Unick, 64, guilty of killing Geer on February 13, which would have been her 57th birthday, the district attorney’s office told CNN.

DNA from a cigarette butt helped California authorities identify the man responsible for the brutal killing of a 13-year-old girl nearly 44 years ago (Sonoma County District Attorney's Office)

The break in the case came in 2003, when investigators developed a DNA profile based on sperm collected from Geer’s underwear. However, the profile did not match anyone whose DNA was available in law enforcement databases, and the case went cold again.

In 2021, the Cloverdale Police Department reopened its investigation into Geer’s death, and enlisted the FBI to help find a potential match to the DNA profile.

“The FBI, with its access to familial genealogical databases, concluded that the source of the DNA evidence collected from Sarah belonged to one of four brothers, including James Unick,” prosecutors said.

After surveilling Unick, FBI agents collected a cigarette he discarded, which confirmed his DNA matched the previous profile.

The Cloverdale Police Department arrested Unick at his home in July 2024. At the time of his arrest, Unick denied knowing Geer or what happened the night of her death. However, during his month-long trial, his story changed.

Unick testified that the teen “propositioned him for sex while he had been playing a video game” at an arcade, and claimed they engaged in consensual sex on a hillside near a river, “implying that Sarah Geer must have been assaulted and murdered later that evening by a phantom man who failed to leave behind DNA evidence.”

After about two hours of deliberations, the jury convicted Unick of murder.

He is scheduled to be sentenced on April 23.

“This guilty verdict is a testament to everyone who never gave up searching for Sarah’s killer,” District Attorney Carla Rodriguez said in a press release. “This is the coldest case ever presented to a Sonoma County jury. While 44 years is too long to wait, justice has finally been served, both to Sarah’s loved ones as well as her community.”