With an accomplice, former drifter Kyle Eckardt is believed to have kidnapped her and raped the wife and mother of two near her Oklahoma City before cutting her throat.
Her body was a “Pretty grisly sight,” according to the man who found her in a meadow in the far west of the state.
Eckardt was already in jail for assaulting a Tulsa woman who's naked body was found in her apartment's bath tub, although the medical examiner could not determine how she died.
The medical examiner could not determine how she died, but as result his DNA was put into the database, which linked him to Engle's death.
A second suspect, Steven A, Boerner was later was identified from a fingerprint on the car's steering wheel but the ex-con died in 1992 in a trucking accident, before he could see justice.
Eckardt entered what is known as an Alford plea to the first-degree murder charge which means a criminal defendant can take a plea deal to avoid a worse punishment without admitting guilty.
He told the judge in writing that he does not admit to the acts but did not want to risk getting the death penalty at trial.
That didn't stop Engle's family venting their fury on him.
According to The Oklahoman Engles older sister, Mary Ann Jones told him the family now finally will have some peace knowing he will never be able to bully, terrorize or torture any woman again.
Her daughter added: “It is cowardly the way you killed my mother. You couldn't even face her.”
He will now serve life in prison.