Mark Jensen Kenosha murder trial: Jensen's sister, pathologist testify

In the new homicide trial for Mark Jensen, a forensic pathologist testified on Friday, Jan. 27 that Jensen's wife, Julie, likely died from complications of antifreeze poisoning – and that it is possible she killed herself. Julie Jensen's best friend also took the stand Friday. 

"She did mention that she thought that Mark might be trying to kill her," said Laura Koster, Mark Jensen's sister and Julie Jensen's best friend.

Jensen's sister, Laura Koster, took the stand Friday to talk about Julie Jensen – and a conversation they had before she died. 

"You shouldn’t stay here," Koster said, suggesting Julie leave Mark."She was my sister-in-law and my best friend."

Laura Koster

Koster testified Julie was worried about her family's history of depression – and on the Monday before her death in 1998…

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"She told me that she was going to the doctor and that she was going to be treated for depression," Koster said.

Mark Jensen trial

Koster said the afternoon Julie Jensen died, she stopped by the Jensen house. It looked like no one was home. After Julie's death, Koster denied telling police she thought her brother killed her best friend – and even denied speakin to police at all. 

"I had no reason to think that Mark had killed her," Koster testified. 

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"I see that there's no conclusive evidence that her death was a homicide," said Dr. Lindsey Thomas, a forensic pathologist. "I think there are many reasons to believe that it was a suicide"

Dr. Lindsey Thomas

Dr. Thomas said she could not come up with an exact cause of death, but ethylene glycol played a significant role.

Thomas said even considering the internet searches on the Jensen home computer, that Mark Jensen was having an affair and Julie's statements to neighbors and others she feared her husband might try to kill her. 

"Oh, I'm certainly aware of the issues that led law enforcement to believe this was a homicide. I'm well aware of those. All I'm saying is, I don't see any physical evidence to support that," Thomas said.

The defense plans to rest its case on Monday. That is also when the oldest son of Mark and Julie Jensen is expected to testify. 

The state will call rebuttal witnesses – and closing arguments could start as early as Wednesday.