Jerry Lynn Burns' internet search history containing violent porn won't be presented as evidence to a jury, but the DNA evidence used to arrest him will, an Iowa district court ruled this week.

Judge Fae Hoover Grinde on Thursday ordered that the DNA used to connect Burns to the murder of Michelle Martinko more than 40 years ago will be presented to the jury when trial begins Monday. She suppressed his search history Wednesday. Hoover Grinde also blocked testimony by Randy Cole, who specialized in sex offender program services before his retirement from the Sixth Judicial District Department of Correctional Services.

Prosecutors hoped to bring Cole to testify about Burns' internet search history as a possible motive for a crime committed four decades ago.

Investigator Jeff Holst of the Cedar Rapids Police Department said during evidence suppression hearings earlier this year that Burns conducted porn searches several times a week. Practically every search began with the phrase "blonde strangulation," he said.

Holst said there were also hundreds of examples of "extremely violent" videos viewed by Burns. One was called "blonde molested after getting stabbed," Holst said. Another search included "sex with freshly dead persons," court records show.

"If the evidence were admitted, Jerry Burns would run the risk of conviction based upon his taste in pornography rather than proof beyond a reasonable doubt that he committed the charged offense," Hoover Grinde wrote in Wednesday's ruling.

MORE:Taking genetic genealogy sites to trial: Iowa homicide case among first of its kind to argue DNA requires search warrant

Burns, 66, was arrested Dec. 19, 2018, and charged with first-degree murder in the 1979 stabbing death of the 18-year-old Martinko. The woman was found dead in her parents' car with 21 stab wounds outside Cedar Rapids’ Westdale Mall, where she'd gone to buy a coat.

Wounds on the teen’s hands showed she fought her killer, but the medical examiner’s office said Martinko was found fully clothed and had not been sexually molested.

In May 2018, after decades without answers, Parabon-NanoLabs, a forensic consultant company, contacted Cedar Rapids police about a new kinship service called Genetic Snapshot in which Parabon would upload the suspect's profile into the commercial DNA database GEDmatch to look for potential relatives.

The database connected the suspect to Brandy Jennings, the suspects' second cousin once removed who lived in Seattle. Genetic genealogists were able to narrow down the DNA profile found at the crime scene "to a specific pool of suspects,” which included Burns.

Investigators in October 2018 followed Burns from his Manchester business to the Pizza Ranch. They retrieved his used drinking straw and sent it to the lab of the state's Division of Criminal Investigation. Burns was arrested that December.

Defense attorney Leon Spies has since argued for the court to exclude any evidence or expert testimony from the trial which stemmed from Burns' DNA or from his family members' DNA.

“Law enforcement investigators authorized Parabon to proceed with this warrantless search of GEDmatch profiles, and in so doing, converted this process to a warrantless government search,” Spies wrote in a December evidence suppression request.

Hoover Grinde on Thursday wrote that Burns didn't present a reasonable expectation of privacy over Jennings' DNA profile. The same goes for the straw, she wrote.

"The law is well-settled that that a person may relinquish property in which the person once enjoyed a reasonable expectation of privacy," she continued. "One does not maintain a reasonable expectation of privacy in property that has been abandoned."

Burns pleaded not guilty in January 2018. His trial is set to begin Monday at the Scott County Courthouse in Davenport.

Anna Spoerre covers crime and courts for the Des Moines Register. She can be contacted at aspoerre@dmreg.com, 515-284-8387 or on Twitter at @annaspoerre.

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