The fatal stabbing case of a Navy sailor whose nude body was found slumped against a fence in his backyard in Point Loma in 1990 went cold for three decades.

But a break in the investigation led police to Brian Koehl, and a DNA sample — collected surreptitiously from an Arby’s cup and straw he threw away one day in 2021 — confirmed their suspicions, prosecutors say.

On Monday, Koehl, 52, went on trial for murder in the killing of 32-year-old Navy Petty Officer Larry Joe Breen.

During opening statements in San Diego Superior Court, prosecutors said Koehl confessed to a friend to fatally stabbing a man who “came onto him.” The defense said it was an act of self-defense, claiming Breen — who was gay — sexually assaulted Koehl.

Koehl has pleaded not guilty to murder. If convicted, he faces 25 years to life in state prison.

Breen was a cook stationed aboard the guided-missile cruiser USS Fox and poised to become a chef for then-President George H.W. Bush at Camp David in Maryland. Koehl was 19 and also a sailor.

Breen’s body was found slouched against his backyard fence on the corner of Nimitz Boulevard and Locust Street around 11:40 a.m. on May 25, 1990. He was naked, with two stab wounds to his neck.

Witness Darryl Albritton testified that he was looking for a home to rent with his girlfriend when he discovered Breen’s body.

Blinds were hanging out of a broken window. It looked like the scene of a scuffle, Albritton said. He called 911 from a payphone at a nearby Vons grocery store.

Inside the unfurnished studio officers found “blood everywhere,” retired San Diego police Officer Denise Dailey testified.

Other evidence included clothing, beer bottles and latent footprints.

The case soon went cold.

In 2001, with advances in DNA technology, a criminalist extracted DNA from evidence and checked local, state and federal databases that contain DNA profiles of convicted offenders, but no matches turned up.

Then, in 2019, investigators turned to genetic genealogy, a technique in which they upload DNA to commercial genealogy websites in search of family members of suspects. The work led investigators to Koehl. They learned that he was stationed in Coronado in May 1990, Deputy District Attorney Lisa Fox said.

In 2021, a Naval Criminal Investigative Service agent monitored Koehl in Knoxville, Tenn., where he was living. When he threw away the Arby’s cup and straw, the agent moved in and collected the items. Later, his DNA was compared to evidence.

“You’re going to hear that the defendant’s DNA is found all over that small apartment,” Fox said. So was his footprint, she said.

Koehl was arrested in Knoxville in July 2022.

In an interview with investigators after his arrest, Koehl admitted he was at Breen’s home the night before his body was found, that they were drinking with four others, Fox said. He told investigators he left and borrowed Breen’s car, and when he returned the next day, he found the crime scene. He said he got blood on his feet and washed off the blood in the shower. He left in Breen’s vehicle, only to abandon it when he thought twice about driving a “dead man’s” vehicle, Fox said.

After Koehl’s arrest, a friend of his came forward with information about the confession. It turned out the friend had reported the information to authorities in Ohio on two separate occasions, but he and the agencies were unaware the crime occurred in San Diego, Fox said.

Defense attorney Alicia Freeze said Koehl was a “small town boy from Ohio” in May 1990. She said Breen lived a “double life” — he was gay at a time when gay men and women were banned from serving in the military.

Freeze characterized the victim as a sexual predator and claimed Breen sexually assaulted Koehl — “a violation that’s haunted my client for 33 years.”

“Brian Koehl was sexually violated, and in defending himself, a life was lost,” Freeze said.

Koehl is out of custody on $500,000 bail. The trial is expected to last two weeks.

This story originally appeared in San Diego Union-Tribune.

©2023 The San Diego Union-Tribune. Visit sandiegouniontribune.com. Distributed by Tribune Content Agency, LLC.

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