Case overview
Michelle Martinko, an 18-year-old high school student, was found stabbed to death in her family’s car in a Cedar Rapids mall parking lot on December 19, 1979. The case remained unsolved for nearly four decades until investigative genetic genealogy linked DNA from the crime scene to Jerry Lynn Burns, who was arrested in 2018, convicted in 2020, and sentenced to life in prison without parole.
The last confirmed movements
Martinko attended a choir banquet at Westdale Mall in Cedar Rapids, Iowa, on the evening of December 19, 1979. She left around 9:00 p.m. and was expected home shortly after. When she did not arrive, her parents searched the area and found her car in the mall parking lot just after 2:00 a.m.
Martinko was dead in the front seat. She had been stabbed multiple times in the face and chest. Her clothing was torn, and there were signs of a violent struggle. No robbery appeared to have taken place. Her purse and belongings remained in the car.
Investigators collected blood evidence from the scene. DNA testing was not available in 1979, but the samples were preserved.
The initial investigation
Cedar Rapids police conducted hundreds of interviews in the weeks and months following the homicide. Investigators focused on individuals who had been at the mall that evening and those with prior contact with Martinko. No clear suspect emerged.
Several men were questioned and excluded. The case generated widespread media coverage in Iowa, but leads dwindled. By the mid-1980s, the investigation had stalled.
DNA profiling became available in later years. Investigators developed a male DNA profile from blood found at the scene. The profile did not match any individual in state or federal databases. Detectives continued to submit the profile periodically, but no match was returned.
The genetic genealogy breakthrough
In 2018, Cedar Rapids police partnered with Parabon NanoLabs, a Virginia-based company specializing in forensic genetic genealogy. The technique involves uploading crime scene DNA to public genealogy databases to identify potential relatives of an unknown suspect.
Parabon uploaded the DNA profile to GEDmatch, a database used by individuals researching family history. The search identified distant relatives of the person whose DNA was found at the crime scene. Genealogists constructed family trees and narrowed the pool of potential suspects.
The investigation led to Jerry Lynn Burns, a Manchester, Iowa, resident who operated a farm and had no prior criminal record. Burns was not previously considered a suspect and had no known connection to Martinko.
Investigators conducted surveillance on Burns and collected a drinking straw he discarded at a Pizza Ranch restaurant. DNA from the straw matched the profile from the 1979 crime scene.
Burns was arrested on December 19, 2018, exactly 39 years after Martinko’s death.
The case against Jerry Lynn Burns
Burns was charged with first-degree murder. He denied any involvement in the killing and stated he did not know Michelle Martinko. His defense attorneys argued that the DNA evidence alone was insufficient to prove guilt beyond a reasonable doubt and questioned the integrity of the genetic genealogy process.
Prosecutors presented forensic evidence linking Burns to the crime scene, including the DNA match and testimony from experts regarding the reliability of genetic genealogy. They also introduced evidence that Burns had no alibi for the evening of December 19, 1979.
The trial took place in February 2020 in Scott County, Iowa, after a change of venue was granted. The jury heard testimony from law enforcement, forensic scientists, and witnesses who recalled Martinko’s final hours.
On February 24, 2020, the jury convicted Burns of first-degree murder. He was sentenced to life in prison without the possibility of parole.
The disputed evidence and appeal
Burns filed a motion for a new trial, arguing that the genetic genealogy evidence should not have been admitted and that the investigation violated his constitutional rights. His legal team contended that the use of third-party genealogy databases without a warrant raised privacy concerns.
The Iowa Court of Appeals rejected those arguments in 2021, affirming the conviction. The court ruled that Burns had no reasonable expectation of privacy in DNA he discarded in a public place and that the use of publicly accessible genealogy databases did not constitute an unlawful search.
Burns also challenged the sufficiency of the evidence, arguing that the DNA match alone did not prove he committed the murder. The appellate court found that the DNA evidence, combined with the lack of an alibi and the absence of any alternative explanation, supported the jury’s verdict.
The Iowa Supreme Court declined to hear further appeals. Burns remains incarcerated.
The investigative turning point
The Martinko case is widely cited as one of the first high-profile cold case homicides resolved through investigative genetic genealogy. The technique gained national attention in 2018 after it was used to identify the Golden State Killer. The Martinko investigation followed shortly after.
Cedar Rapids police credited advances in forensic science and the preservation of evidence from 1979 as critical factors in solving the case. The DNA profile developed from the original blood samples remained viable for nearly four decades, allowing investigators to use newer technologies as they became available.
The case also prompted broader debate regarding the use of consumer DNA databases in criminal investigations. Privacy advocates raised concerns about the potential for law enforcement to access genetic information without consent, while prosecutors and victim advocates argued that the technique provided a necessary tool for solving violent crimes.
Where to look next
- Documentary: “Genetic Detectives” (ABC)
- Book: “I Know Who You Are: How an Amateur DNA Sleuth Unmasked the Golden State Killer and Changed Crime Fighting Forever” by Barbara Rae-Venter
- Podcast: “The Deck” (audiochuck)
