The 1975 murder of a Maryland woman was finally solved with the help of an old cassette tape and the mugshot of the victim, authorities announced Tuesday.

The cold case of Roseann Sturtz, who was strangled to death after meeting her assailant at a bar on Aug. 24, 1975, was a mystery for decades until Howard County police revived the probe late last year and uncovered evidence a convicted killer already in prison committed the crime.

Detectives discovered a 1981 audio tape in which Charles William Davis Jr., then incarcerated at Jessup Correctional Institute, was asked about the murder in exchange for not facing charges in the case.

At the time, Davis could not identify Sturtz, who lived in Baltimore and went by Ann, as one of his victims after he was shown a photo taken of her several years before her murder, police said.

But Howard County police Cpl. Wade Zufall then brought Davis from the same jail to police headquarters last year to interview him again 44 years later.

He showed Davis a more recent photo of Sturtz – her in a mugshot — from a month before she was killed.

This time he identified her as one of his victims and admitted to the slaying.

Footage released from the interview shows Sturtz nodding his head as he took a look at the photo.

“In November 2024, we were grateful to have all the case details, learned Roseann’s actual date of death and receive the closure we have been praying for all these years — finally put to rest the answers we never had,” Sturtz’s family said in a statement through the police department.

Davis told police after meeting Sturtz at a bar, the pair got into an argument before the murder, Zufall said.

Davis landed on authorities’ radar in 1981 after police studied Davis’ confirmed victims and compared them to Sturtz, Zufall said during a press conference.

Davis can’t be charged with the murder, but is already in prison for life for other killings.

“His main reason why he wanted to talk to me … was he wanted to give closure to the family,” Zufall said.