Prosecutors on Tuesday shared the results of DNA testing said to link Justin Halstenberg to the Line Fire — a blaze that claimed more than 44,000 acres of San Bernardino National Forest land.
But if the jury was looking for a clear sign that Halstenberg was involved with the fire, they did not get one. Numerous coins found at the scene showed Halstenberg could not have been the contributor, while the defense pointed out San Bernardino County had lowered its DNA testing threshold shortly before the Line Fire began.
‘The DNA found on those coins is not his — it’s not possible’
The prosecution’s star witness May 6 was Dennis Key, a 27-year veteran criminalist in the scientific investigation unit of San Bernardino County Sheriff’s Department.
Key’s passion for DNA testing was evident during his testimony, as he provided detailed explanations on where DNA is found, how it is analyzed, and how much DNA is needed to include or exclude a suspect as a possible DNA “match.”
According to Mayer, he was tasked with testing the DNA of four items found at the scene of the Line Fire and nine items found at the scenes of three blazes that occurred in Riverside County in 2023 — fires the prosecution alleges were also Halstenberg’s handiwork.
The items included numerous coins, razor blades, a construction staple, two Marlboro cigarette boxes, paper towels and a plastic zip tie.
Absent was the yellow lined paper that crime scene specialist Shira Johnson testified to swabbing in testimony April 28. That paper was also considered to be key evidence of Halstenberg’s involvement with the Line Fire.
Three excluded Halstenberg as the DNA contributor.
Seven did not contain sufficient DNA to determine a contributor.
One included low-end “moderate” support that DNA was contributed by Halstenberg and another contributor (320 on a scale of 100 to 10,000).
Two included “very strong” support that DNA was contributed by Halstenberg and another contributor. Neither of those items was associated with the Line Fire scene.
The three items excluding Halstenberg were all coins — the items investigators say were used to help start the Line Fire. Of six coins tested from the Line Fire and Riverside County sites, three excluded Halstenberg as a possible contributor, two had insufficient DNA to test and one had moderate support for Halstenberg’s DNA being present.
“The DNA found on those coins is not his, it’s not possible?” defense attorney Luke Byward confirmed with Key.
“That is correct,” Key answered.
According to Key, the seven items with insufficient or no DNA do not necessarily support Halstenberg’s innocence, however.
“An absence of DNA won’t exclude (him),” he said.
Central to the defense’s cross examination was the fact that San Bernardino County’s crime lab recently lowered its DNA quality threshold — the quality level of DNA it says it needs to create a reliable DNA comparison.
Prior to September 2024 — the month the Line Fire began — analysts required a level of 100 to analyze the DNA in question. But starting in September, that number was lowered to 30.
Why does it matter? For starters, the higher standard would have prevented some evidence from being analyzed at all. In the case of the only coin found at the Line Fire scene with “moderate” support of Halstenberg’s DNA, for instance, two of the 23 points analyzed on that coin had values over 100. One was the X-chromosome, which all humans have, meaning it would not have served to include or exclude Halstenberg as a suspect.
“Is it common in the scientific community for the threshold to be 30?” Byward pressed.
“It is common in our laboratory,” Key said.
According to the prosecution, the drop in standards was a pure coincidence and went into effect before Key began to analyze Halstenberg’s DNA.
“Would it be accurate to say it had nothing to do with this specific case?” prosecutor Justin Crocker asked.
DNA strongly linked to Riverside, not Line Fire
Two of the items tested by Key showed “very strong” conclusive support for Halstenberg being the contributor. Those items were a Marlboro cigarette box and paper towels — neither of which were found at the Line Fire scene.
Instead, those items were found at or near the scene of blazes set in Riverside County in 2023 — fires for which Halstenberg is not facing charges.
Cal Fire investigators who testified April 28 said of two Marlboro boxes found at or near the 2023 blazes, one was found 500 feet from the origin of the fire and could not have been the incendiary device that started it. Neither the prosecution nor defense noted if the Marlboro box likely to have Halstenberg’s DNA was the one found at the scene or far away from it.
The defense team had not completed its cross examination of Key by the end of testimony May 6.
This is a developing story. The Grizzly will continue to provide updates as they become available.
