Trial of former Northwestern professor charged in killing of boyfriend in 2017 begins

Wyndham Lathem was a successful and powerful man who enlisted a stranger to allegedly help him kill his boyfriend, Trenton Cornell, while he slept, Cook County prosecutors said in court Monday.

And after they stabbed Cornell 78 times in Lathem’s River North condo — a place where Cornell felt safe and secure — Lathem, then a Northwestern University microbiologist, and Andrew Warren fled the city, leading to a nationwide manhunt in the summer of 2017, prosecutors said in Leighton Criminal Courthouse.

But Lathem’s attorney said Cornell was killed by Warren because he was jealous.

Warren, a British national, killed Cornell because a day before, Lathem ended his romantic relationship with Warren, defense attorney Kenneth Wine argued. Lathem only fled with Warren because he was horrified by the fatal attack and wanted Warren to confess, Wine said.

“This was nothing more than a crime of opportunity that had two victims,” Wine said. “Andrew Warren took the life of Trenton Cornell and ruined the life of Dr. Lathem.”

The differing perspectives came as the long-anticipated trial for 47-year-old Lathem, who faces first-degree murder charges, began after nine women and six men were selected as jurors before Judge Charles Burns on Monday.

Warren pleaded guilty to murder charges in 2019and was sentenced to 45 years in prison as part of a plea agreement with prosecutors that would potentially allow him to serve the bulk of his sentence in England. He is expected to testify against Lathem during the two week trial.

Prosecutors previously said Lathem and Warren hatched the plan as part of a violent sexual fantasy that was supposed to end with the two men killing each other. But during opening statements, Assistant State’s Attorney Matthew Thrun only noted that Lathem and Warren planned to commit suicide together.

Wine acknowledged his client’s kinky and consensual sexual relationship with 26-year-old Cornell, which included knife play, bondage and, at times, more than one partner.

In many cases, Wine said, Lathem and Cornell would get high on meth to heighten sexual pleasure, and they used “mosquito” as their safe word.

Warren had joined Lathem and Cornell in the bedroom July 27, 2017. Earlier in the evening, Wine said, Lathem ended things with Warren, who allegedly “catfished” the microbiologist.

Wine said Warren “killed Trent Cornell out of the most common human emotions: jealousy.”

However, Thrun accused Lathem of making every decision regarding every aspect of the crime.

“He provided the crime location. And when he was on the run, he was behind the wheel... he decided where to go,” Thrun said.

Thrun noted that Lathem’s blood was found around the condo, including on two knives. Thrun also warned jurors that they’ll see a video where Lathem apparently confesses to the fatal attack.

“He’s going to tell you, ‘I killed him, I did do it, it wasn’t an accident, it was a mistake … and I will regret it with every fiber of my being,’” Thrun said, quoting the video.

Wine said Lathem feels “morally responsible” for Cornell’s death and has expressed “remorse at what he made happen.”

Before the trial ended for the day, Cornell’s mother took the stand for the prosecution. Charlotte Cornell identified her son in a photo that was taken in her backyard in her small town Michigan town.

Cornell was smiling in the photo. That smile and joy is “absolutely” how his mother remembers him being the last time she saw him.

Lathem’s trial will resume Tuesday.