Michelle Martinko Was Stabbed 29 Times — Then Her Case Went Cold. Police Caught Her Killer 40 Years Later

Dateline is shining a light on a homicide that lingered in limbo for nearly 40 years.

Michelle Martinko was found stabbed to death in her car outside a local mall in December 1979. After investigators ruled out people in her circle, the Cedar Rapids Police Department began to believe the 18-year-old Iowa teen was killed by a stranger who stabbed her 29 times. She wasn’t robbed, even though she had $186 with her, and investigators found no evidence of sexual assault.

“She was nervous about going out to the mall by herself,” her friend Tracy Price told CBS’s 48 Hours in December 2023. “She had told someone that she felt like she was being followed.”

A major break didn’t come until 2006, when a detective located what he believed was the killer’s blood, NBC News and The Gazette reported. That discovery ultimately pointed investigators to Jerry Burns, whose DNA matched material recovered from the crime scene.

Burns was arrested in 2018 on the 39th anniversary of Martinko’s death, and he was convicted of her murder in 2020.

Here’s what to know about Martinko’s murder, why the case went unsolved for so long, and where her killer is now.

Martinko Was Killed in 1979

On Dec. 19, 1979, Martinko stopped at Westdale Mall in Cedar Rapids, Iowa, to pick up a new coat. She never made it home.

Around 4 a.m. the next day, police found her body in the passenger-side footwell of her family’s car, parked in the mall lot. She had suffered multiple stab wounds to her face and neck, along with defensive cuts on her hands, 48 Hours reported.

Investigators also found signs suggesting the attacker wore rubber gloves. Nothing was taken from her—cash included—and her autopsy indicated she had not been sexually assaulted.

The Investigation Went Cold for Decades

In the early days of the case, people close to Martinko suspected an ex-boyfriend. Police questioned him, but he had an alibi for the time of the killing, and no evidence ever tied him to the crime.

“By 1986, this case is sitting on ice,” Cedar Rapids police investigator Matt Denlinger told 48 Hours.

Nearly three decades later, cold case detective Doug Larison discovered that blood scrapings taken from the car’s gear shift had been sent for testing—but the results were never pursued, 48 Hours reported. Additional testing later determined that the blood on the gear shift and on Martinko’s dress contained male DNA.

Genetic Genealogy Narrowed the Suspect Pool

Even with DNA evidence, the case still took years to move forward. Investigators eventually used genetic genealogy, which compares crime-scene DNA to profiles voluntarily uploaded to public ancestry databases to locate possible relatives of a suspect. According to 48 Hours, a distant relative of the killer had submitted DNA, which helped lead police to three brothers living in Iowa.

After investigators collected samples from each man, one brother—Burns—was identified as an exact match to the male DNA recovered from the crime scene.

Burns was arrested in 2018, on the 39th anniversary of Martinko’s murder.

Burns Was Convicted in 2020

Burns, an Iowa business owner, pleaded not guilty to first-degree murder and told police he had never met Martinko. People who knew him described him as quiet and easy to talk to, and some struggled to believe he could have committed such a crime.

“You’d have a hard time convincing me that Jerry did this,” Mike McElliott, who had known Burns for 40 years, told KCRG at the time of the arrest. “I just, I just could not believe that.”

In February 2020, Burns was found guilty of Martinko’s murder and later sentenced to life in prison without the possibility of parole, KCCI reported.

“Michelle played a critical role in identifying her own killer,” Martinko’s brother-in-law John Stonebraker said in a video. “The defensive wounds on her hand show it. She fought so hard that she was able to deflect the killer’s knife so that he stabbed himself, leaving the blood that caught him.”

He added, “In a very real way, Michelle became her own best witness.”

His Appeal Was Denied

Burns later hired attorney Kathleen Zellner—best known for representing Steven Avery, one of the subjects of Netflix’s Making a Murderer—to challenge his conviction, per KCRG. He argued that investigators violated his constitutional rights by collecting his DNA from a straw he discarded at a pizza restaurant.

The Iowa Supreme Court denied the appeal in March 2023. Burns has been held at the Anamosa State Penitentiary since his 2020 conviction.