Prosecutions' DNA expert in Michelle Martinko murder trial says lab tested only for blood

Only DNA profile developed belonged to Jerry Burns, criminalist says

Iowa Division of Criminal Investigation criminalist supervisor Paul Bush is questioned by First Assistant Linn County At
Iowa Division of Criminal Investigation criminalist supervisor Paul Bush is questioned by First Assistant Linn County Attorney Nick Maybanks on Friday at the Scott County Courthouse in Davenport. Bush was a rebuttal witness for the prosecution in a murder trial for Jerry Burns, 66, of Manchester. Burns is accused of fatally stabbing Michelle Martinko, 18, of Cedar Rapids, on Dec. 19, 1979, at Westdale Mall in Cedar Rapids. (Olivia Sun/Des Moines Register)

DAVENPORT — A DNA expert testified Friday, in rebuttal testimony, that the only biological fluid screened was blood found in the DNA profile developed from Michelle Martinko’s dress, and was consistent with Jerry Burns.

Because Martinko, 18, of Cedar Rapids, was fatally stabbed during a struggle, the suspect likely cut himself, Paul Bush, a criminalist supervisor with the Iowa Division of Criminal Investigation, testified at the end of the second week of a Burns’ first-degree murder trial. 

Bush said the major contributor of the profile was Burns. Less than 1 in 100 billion of unrelated individuals would have the same profile.

This testimony was to rebut a forensic consultant for the defense, who said the blood concentration was so low that he didn’t think it could come from suspect cutting himself. He said he didn’t know if the DNA contained blood or from another bodily fluid such as mucus or saliva.

Michael Spence, a hired defense expert and the only witness called by the defense, also said Thursday that Burns’ DNA found on the evidence could have happened through transfer. DNA can be transferred through a handshake or touching an object and could be passed to another person, Spence said.

Burns, 66, of Manchester, is accused of killing Martinko in her parents’ car, which was parked behind J.C. Penney at Westdale Mall. Her body was found by police Dec. 20, 1979.

According to testimony last week, the teen was stabbed 29 times. The fatal stab wound was to the sternum, which penetrated her aorta, and she bled to death, a pathologist testified.

A public genealogy database, GEDmatch, helped authorities identify Burns as a match to the DNA found on the back of Martinko’s black dress and car gearshift. Burns was arrested Dec. 19, 2018 — on the 39th anniversary of her death.

The trial, moved to Scott County because of pretrial publicity, will continue Monday with closing arguments.

Motion for mistrial denied

Defense attorney Leon Spies asked for a mistrial after First Assistant Linn County Attorney Nick Maybanks called the DNA found on the dress and gearshift blood. Spies argued that all the witnesses had said they couldn’t rule out other biological fluids.

Maybanks argued the only tests conducted screened for blood, and none of the prosecution’s witnesses said it wasn’t.

“This isn’t a shocking revelation,” Maybanks said. “The state has always said it’s blood.”

6th Judicial District Judge Fae Hoover, outside the presence of the jury, denied Spies’ motion for a mistrial.

In open court, Hoover told the jury to disregard Maybank’s statement about blood. She said “none of the experts could definitively say the DNA came from blood” and couldn’t exclude the possibility that it came from other biological sources. If is up the jury to make that determination, she added.

Maybanks asked if the crime lab screened or tested for other fluids such as, saliva and sweat or skin cells.

Bush said no.    

How evidence was handled

Maybanks asked if Bush, a former crime scene investigator, was concerned the evidence — Martinko’s clothing — was packaged together, which Spence, who didn’t do lab work and only reviewed the criminalists’ work in this case, said could result in transfer DNA.

Bush said this wasn’t a concern. He has packaged items together if it was all from one person — the victim or all from the suspect. As an example, the bedding in a sexual assault case would be packaged together, he added.

Maybanks asked there was a concern about repackaged evidence.

Bush said the policy is to return evidence to law enforcement in the original packaging, unless the package is badly torn and could cause contamination. There is the possibly of having some transfer, he said, but as long as there is no outside transfer, it’s not a concern.

Former criminalists testified last week that the evidence had been repackaged over the years when tested at different times or was left in original packaging. 

There was enough DNA for testing, witness said

Maybanks asked about the amount of DNA tested. Was there too little to test, as Spence suggested.

Bush said there was enough.

The nine areas on Martinko’s dress screened indicated blood, Bush said. Eight were consistent with Martinko’s DNA. Only one profile was developed — that of Burns. There were no other known profiles, Bush said.

Spies, on cross-examination, said Bush couldn’t positively say Burns’ DNA came from blood, sweat or saliva.

Bush agreed.

Spies asked if Bush’s DNA is on the witness stand’s microphone, and Bush said that was possible.

Maybanks, on redirect, said if a known set of circumstances were confirmed, such as someone was sitting on mall bench, that would need to be confirmed to determine if secondary transfer DNA was possible.   

Bush said if there was a video to see that, then it probably couldn’t be confirmed to say it’s secondary transfer DNA from bench.

Spence said Burns' DNA could have been from secondary transfer, which could indicate he might not be the killer. 

Facts, data and history are needed, or “we’re just guessing,” Maybanks asked.

Bush said yes.

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