Investigator: Jerry Burns' "fetish" for violent internet sex shows possible motive for killing Michelle Martinko

Jerry Burns stands with his lawyer Leon Spies (right) during a recess in the continuation of a suppression hearing for e
Jerry Burns stands with his lawyer Leon Spies (right) during a recess in the continuation of a suppression hearing for evidence in the case of Burns of Manchester at the Linn County Courthouse in Cedar Rapids on Thursday, Jan. 16, 2020. Burns is accused of murdering Michelle Martinko in 1979. (Rebecca F. Miller/The Gazette)

CEDAR RAPIDS — Police investigators couldn’t find evidence that Jerry Burns and Michelle Martinko knew each other. Yet they had a DNA match linking the Manchester man to the Cedar Rapids teenager, slain in 1979 outside the Westdale Mall.

It wasn’t until decades after the killing that investigators began to link the emotions of a motive with the science of DNA.

Authorities pored over 300 pages of internet search terms and 400 pages of website history, according to court testimony Thursday — almost all of it involving blonde females and most web searches starting with queries about blonde strangulation.

Burns seemed to have a “fetish” for these violent, sexual themes, Cedar Rapids police Investigator Jeff Holst testified.

Burns, charged with first-degree murder in the cold case stabbing of Martinko, is asking the court to toss out DNA and other evidence because they were obtained without a warrant and represented violations of privacy and other rights.

Burns’ attorney, Leon Spies, also argued in his suppression motion that the computer evidence is irrelevant because it’s from 2018 — 38 years after Martinko’s death.

A hearing over whether to allow the evidence at trial continued Thursday for a second day.

The majority of the search activity and history on Burns’ computer was sexually graphic and more “deviant in nature,” said Holst, who investigates sex crimes and internet crimes against children.


Last week, a police investigator explained how using a public genealogy database — called GEDmatch — led to Burns being identified as a match to the DNA evidence found on Martinko’s dress and gearshift of her car, where her body was found Dec. 20, 1979.

Police covertly obtained Burns’ DNA from a drinking straw he left it on a table after eating lunch Oct. 29, 2018, at the Pizza Ranch in Manchester, testimony showed.

Holst said that in reviewing Burns’ computer, he found hundreds of searches and website visits — a pattern that happened several times a week. But the software he used allowed him to review history and activity only to January 2018.

On cross examination, Spies asked Holst if he had expertise in psychology or forensic psychology. Holst said he didn’t, but department officials and First Assistant Linn County Attorney Nick Maybanks did consult an expert who specialized in sex offender assessment and treatment to explain what this evidence indicates in this case.

In earlier testimony, Matthew Denlinger, a Cedar Rapids police investigator who testified last week, was recalled to testify about Burns’ interview with police Dec. 19, 2018.

Denlinger said he intentionally chose that day to interview Burns because it was the anniversary of Martinko’s death. He said he thought Burns might have a “conscience.”

But he said he and another investigator had no plans to arrest Burns that day. They wanted to try to get an explanation for why Burns’ DNA was found at the crime scene and to get a DNA sample from Burns to confirm the DNA obtained from the drinking straw.

Denlinger said they went to Burns’ business, Advanced Powder Coating Concepts in Manchester, and he agreed to talk with them.


Burns repeatedly said he didn’t know how his DNA was found at the crime scene. He said he remembered the case from seeing it in the news, but didn’t know Martinko and didn’t have anything to do with it, Denlinger testified.

He asked Burns for a sample of his DNA, but Burns said no — not without an attorney. But he never asked for an attorney, Denlinger said.

Denlinger then told him he had a search warrant for his DNA. Burns kept pointing to the swab, he testified, and saying, “Test it. See if it is.”

Burns told the investigator about 25 times to test him, Denlinger said. He said Burns had no memory of being at the crime scene.

“If I was there, I don’t know,” Burns told Denlinger. “As far as I know, I wasn’t there.”

Denlinger told him authorities would come back to talk to him after they got the results of the DNA test. But then Denlinger’s supervisor, who had been listening to the recorded interview from across the street with other officers, sent Denlinger text message telling him to arrest Burns.

Burns was read his Miranda rights and taken to the police department. On the way, Burns continued to talk. During this time, according to the testimony, he made a reference to “blacking out” but didn’t explain it.

At the department, Burns sked for a lawyer.

Spies, on cross examination, asked if Denlinger had permission from Burns’ two brothers and a distant cousin to access their DNA in developing a suspect pool. Denlinger said they were uploaded to GEDmatch by Parabon NanoLabs, a private company the department worked with. But Denlinger did get consent from Janice Burns, Burns’ first cousin, and collected her DNA for testing, he said.


Spies asked if he had consent from Burns to take the lunch straw for testing. Denlinger said no. He testified last week he took the straw after it was discarded.

The hearing will continue in Linn County District Court, though a date has not been set.

Comments: (319) 398-8318; trish.mehaffey@thegazette.com

Give us feedback

We value your trust and work hard to provide fair, accurate coverage. If you have found an error or omission in our reporting, tell us here.

Or if you have a story idea we should look into? Tell us here.