DNA evidence from an alleged sexual assault in 1994 has led to the arrest of a man for a 43-year-old murder in California.

Harold Carpenter, 63, is believed to have killed Patricia Carnahan in 1979, the El Dorado County District Attorney’s Office in California said.

Ms Carnahan’s body was found at a campground at Lake Tahoe on 28 September 1979. Her identity was not discovered until 2015 when the case was re-examined.

Her body was exhumed and relatives recognised a pendant she wore and matched her DNA.

Mr Carpenter was identified after a rape kit – used to gather evidence after alleged sexual offences – was finally tested, NBC News report.

Evidence from an alleged 1994 sexual assault in Spokane, Washington, was analysed and his DNA was found to match traces collected from Ms Carnahan’s body, according to the district attorney’s office.

The rape kit was tested as part of a nationwide effort to address a backlog of untested evidence.

When the sexual assault happened it was deemed “unprovable,” the district attorney’s office said, and the victim has since died.

Spokane police said Mr Carpenter was arrested in 1994 and booked on a second-degree rape charge, but the case was suspended and charges were never formally filed.

The kit was submitted for testing last year, it added.

Mr Carpenter was arrested on Monday at his apartment in downtown Spokane.

He faces a murder charge in California, the district attorney’s office said.