British suspect to testify against professor in Chicago stabbing

CHICAGO — A British man charged in the 2017 stabbing death of a man in Chicago has pleaded guilty in a deal that calls for him to testify against a former Northwestern University professor also charged in the killing in exchange for a 45-year-prison sentence.

Oxford University employee Andrew Warren was scheduled to go on trial next week but attorneys announced at a Monday hearing that he has agreed to testify against Wyndham Lathem.

Police began a manhunt for the pair in August 2017 after the body of Lathem’s boyfriend, Trenton Cornell-Duranleau, was discovered in Lathem’s Chicago apartment. He had been stabbed dozens of times.

The two men then fled to the West Coast and turned themselves in to authorities in California eight days after the killing.

Warren, who had arrived in the United States on his first visit a few days before the attack, surrendered to officers in San Francisco on Aug. 4. Later that day, Lathem, who was fired by Northwestern after authorities began searching for him, turned himself in to federal agents in Oakland.

Prosecutors have said the fatal stabbing was part of a sexual fantasy hatched in an online chat room between Lathem and Warren, whose plan included killing someone and then themselves.

Cornell-Duranleau, the 26-year-old boyfriend of Lathem, was stabbed about 70 times and with such brutality that he was nearly decapitated. His throat was slit and his pulmonary artery torn.

Cornell-Duranleau, a Michigan native, had been asleep in Lathem’s high-rise Chicago condo when Lathem began plunging a 6-inch drywall saw knife into his chest and neck, prosecutor Natosha Toller said at a previous hearing. When the victim awoke, he began screaming and fought back.

Toller said Lathem then yelled at Warren, who was standing in a nearby doorway,...