On day 10 of testimony in the Chad Isaak trial, the defense had its opportunity to address forensic evidence that the prosecution says links Isaak to the victims.

The defense’s approach was to focus on the phrase “could not be excluded.”

The defense also questioned the forensic biologist about the transfer of DNA and possible contamination of the DNA evidence.

The defense looked to strike back on Tuesday, cross-examining a forensic biologist who testified he could not exclude Robert Fakler or Lois Cobb’s DNA from Isaak’s truck.

“You didn’t say it was a match, right?” asked Defense Attorney Luke Heck.
“I did not,” said Kyle Splichal, a forensic biologist with the Defense Forensic Science Center.
“You didn’t say it was consistent either,” said Heck.
“I did not,” said Splichal.
“You said that it could not be excluded,” said Heck.
“That is correct,” Splichal replied.

The defense also questioned the witness about the possibility the DNA evidence was unintentionally mixed together.

“If you have two separate crime scenes that are a fair distance apart, if one person were to even wear gloves at one crime scene and then not change those gloves and hold onto a cell phone, hold onto their own steering wheel, they would then potentially be transferring DNA from the cell phone to their gloves and if they wore those gloves all the way to another crime scene and then handled evidence, there would be a potential for contamination,” said Splichal.

The state, on its redirect, struck back.

“In this case where there’s been testimony that proper PPE was utilized, that the selection process altered gloves every time a new swab was collected, that the evidence was secured, and that nobody that had contact with that blood touched this vehicle prior taking to these swabs, would that ensure the integrity of these results?” said Prosecuting Attorney Gabrielle Goter.
“If everything you described, yes. That sounds like protocol was followed,” Splichal replied.

The state also called to the stand a firearms and tool mark examiner.

He testified that the recovered bullets he examined came from the .38 caliber family, but he was unable to determine if they were all fired from the same gun.

Next up on the stand was a forensic chemist, and she testified about another link between Isaak and the victims, saying she found fibers from a facemask and orange sweatshirt found in Isaak’s dryer that matched orange fibers found on the victims.

The defense on cross-examination questioned whether the results were influenced by investigators.

“Per conversation with Pat Haug, this was from RJR vehicle, correct?” said Heck.
“Yes, again I wasn’t sure what vehicle this was from so if it was from Mr. Isaak’s own vehicle it may not be that valuable,” said Amy Michaud, a forensic chemist/trace evidence examiner with the Bureau of Alcohol, Tobacco, Firearms and Explosives.
“At the end of the day, you’re relying on Pat Haug telling you where these items are from in formulating your opinions and connections, correct?” asked Heck.
“It’s not formulating my opinions but realizing what the importance is. It doesn’t make sense to compare a bunch of items from one individual to the other,” said Michaud. “Like I didn’t compare any of the fibers from the victim’s clothing to each other because we know they were together and it didn’t have evidentiary value. So you have to have some of the story to know what has potential value when you’re looking at items like trace evidence.”

The state worked to piece together the elements of the story for jurors so they will find Isaak guilty beyond a reasonable doubt.

The defense worked to sow seeds of doubt in the juror’s minds that Isaak committed the crime.

On the 10th day of testimony, the state rested its case. The defense is expected to begin calling its witnesses Wednesday morning, however, it expects to be wrapped by noon, so we should be done with trial testimony on Wednesday.

Closing arguments are scheduled for Thursday morning.

To follow the full trial, you can catch our live stream on our website.