Detectives made a break in the murder of a Florida woman nearly 40 years ago when DNA in the case was linked to her son’s former football coach, police said Thursday.

Joseph Clinton Mills, 58, was identified as a suspect through a genetic genealogy database in the 1981 slaying of Linda Patterson Slaten, according to the Lakeland Police Department.

The 31-year-old mom had been found strangled to death in her Lakeland apartment with the screen removed in her bedroom, authorities said.

She was discovered with a hanger around her neck and there was evidence that she had been sexually assaulted, officials said.

One of her sons, Timothy Slaten, told detectives that Mills, who was his youth football coach, dropped him off after practice. Mills, who was 18 at the time, was questioned, but claimed he had never been in the apartment or had sexual relations with the mom.

The case was reopened in January 2017 with the help of the public genealogy databases, which match suspects’ DNA with relatives who voluntarily upload their samples, authorities said.

“Due to the advances of technology in DNA testing and the sheer passing of time, Detective Melissa Hancock pursued various investigative avenues in the case and resubmitted evidence in the case for additional testing and comparison,” Lakeland Assistant Police Chief Mike Link said Thursday at a press conference.

Mills was interviewed by authorities in December and arrested on charges including first-degree murder, sexual battery and burglary, authorities said.

“He is a monster, there is no doubt about it,” Slaten’s son Jeff told reporters.

Genealogy databases have helped authorities crack numerous high-profile cases, including the suspected Golden State Killer in April 2018.

A 1998 case was solved earlier in the week when the database GEDmatch linked Robert Brian Thomas to the pair of sexual battery cases in the Florida towns of Venice and Indian Rocks Beach, authorities said.