On Wednesday, November 25, 1998, Julie Jensen volunteered to help out in her son's third-grade classroom in Kenosha, Wisconsin. While she was there, she confided in her son's teacher; she feared that her husband was attempting to poison her, in part due to his Internet search habits.

“She had found a paper listing things to buy in her husband's stuff,” the teacher, Theresa DeFazio, told investigators. “She said it listed syringes and names of drugs on it. Then she said that she thought he might try to kill her with a drug overdose and make it look like a suicide... One other time she had mentioned that it bothered her how every time she walked into the room when her husband was on the computer, he always turned it off or covered it quickly. She asked him why once, but he said he was doing business stuff, and he was done.”

Around the same time, Julie confided similar concerns to her next-door neighbor, Tadeusz Wojt.

"I saw Julie, and she stated to me that she was afraid that [her husband] Mark was putting poison in her food or drink, and she did not eat all weekend," he told investigators. "Julie was shaking and crying. She was in bad shape Julie also stated Mark would call up things on the Internet about poisoning on the Internet, and he would leave it on the screen for her to see. Some of the things were undetected poisoning that was on the computer.” Julie also left a note with Wojt to be turned over to the police in the event of her death.

On December 3, two police officers responded to a distress call at the Jensen home. They found the husband, Mark, in the kitchen. He pointed them down a hallway to a bedroom where the police found Julie's body, lying facedown on the bed “with her face partially buried in a pillow.”

Toxicology reports would later determine that Julie had died from ingesting large quantities of ethylene glycol, the key ingredient in antifreeze. And she hadn't done it just once, as one might expect if this were a suicide; toxicology reports found that the ethylene glycol had been consumed multiple times and had formed oxalic acid crystals in her kidneys. Initial lab work suggested that “there were at least two doses of ethylene glycol,” including “an acute ingestion at or near the time of death.”

It could not have been a pleasant way to go. Mark Jensen told a detective who arrived to search the scene that day that his wife Julie “could hardly sit up when she awoke at 7:30am on the morning of December 3, that she “was not able to get out of bed,” and she “was not able to move around and function.” Rather than calling an ambulance, Mark Jensen propped his wife up in bed and then did something that looked odd—he went to his computer and searched the Internet for "ethylene glycol poisoning” at 7:40am.

Within the next hour, he left to take their son to preschool, but not before (in the court's words) "double deleting" his Internet history that morning. By 4:35pm, Julie was dead, with a concentration of ethylene glycol in her stomach that suggested ingestion within the previous 12 hours.

An interest in antifreeze



The case startled Kenosha, a working-class town where I spent my own high school years, but it wasn't a simple one to prosecute. Julie had a history of depression; she had once had an affair that her husband could never forgive; Mark placed penis-oriented pornographic photos around the home, which Julie seemed to think came from her ex-lover (the police had apparently been called about prowlers); Mark had started an affair of his own and planned to clean up the "details" of his life to be with another woman.

When it became clear that Mark was a suspect, Jensen's relatives started a website devoted to his innocence, one that claimed Julie came from a family with a history of both depression and suicide attempts. In their view, most of the evidence in the case had been carefully planted in advance by Julie, who hoped to frame her husband for attempted murder. In this account, Julie was the one who took the antifreeze, but she never intended to die; she intended to “call 911 and be revived.” The family took particular issue with the note left with Wojt, which they construed as the main evidence against Mark, and which was simply another plant by Julie.

But the authorities didn't buy this explanation. Four years after Julie's death, in 2002, the local district attorney filed a first-degree intentional homicide charge against Mark Jensen, and that initial complaint drew heavily on what was still novel in 1998: the use of an Internet search history to establish guilt.