Convicted murderer Jerry Burns, 66, is scheduled to be sentenced Friday in the 1979 murder of Michelle Martinko, 18. Court is set to start at 2:30 p.m. ET / 1:30 p.m. CT. You can watch in the player above.

The story should be familiar to those following newly solved (or possibly solved) high-profile cold cases: There was a murder decades ago, and the case went unsolved with no sign of a suspect. Years passed, and the recent use of a genealogical database established a link between the crime scene and a possible perpetrator.

The Martinko case followed such a pattern. She was stabbed to death in her parents’ car outside the Westdale Mall on December 19, 1979. There was no evidence of robbery or sexual assault, authorities said. The motive was unclear.

The case went cold. The technology developed. Parabon NanoLabs helped investigators with testing on the case. DNA found on Martinko’s clothes pointed them toward three brothers, Assistant Linn County Attorney Nick Maybanks said in closing arguments last February. One of those brothers was Jerry Burns.

The defendant denied being the killer, but investigators said they were able to confirm it was him through DNA testing.

Authorities worked to show that it was really was him, and that there’s no other way his DNA ended up on Martinko’s clothing. The defendant was 25 at the time.

Appeals are typical enough in criminal cases. Burns is no exception. Since the defendant was found guilty, his attorney has argued the genetic testing was unconstitutional. Burns remains a guilty person in the eyes of the law, and the judge is set to hand down a mandatory life sentence on Friday for first-degree murder.

“We still are left with the fact that we’ve lost my sister,” Martinko’s sister Janelle Stonebraker told The Law&Crime Network after the guilty verdict. “We lost all of those years that she didn’t live, and she had such a bright future, and she was looking forward to college. And we lost all of that.”