CHICAGO (AP) — The murder conviction of a former Northwestern University professor who was sentenced to decades in prison for killing a boyfriend has been overturned because he was not allowed to consult with his trial lawyer during an overnight recess.

An Illinois Appeals Court panel on Friday overturned Wyndham Lathem's 2021 first-degree murder conviction.

The panel ruled 3-0 that Lathem's right to counsel was violated and remanded the case back to the trial court.

In its opinion, the appeals court said restrictions during overnight recess should only be given in “only exigent and unusual circumstances."

It continued that the "defendant’s right to unrestricted access must prevail over any fears of coaching, which should be addressed through exposure on cross-examination or through scheduling.”

Lathem was sentenced in 2022 to 53 years in prison for the 2017 stabbing death of Trenton Cornell-Duranleau. At the time, Cook County Judge Charles Burns called the killing “cold-blooded” and an “execution.”

Prosecutors said Lathem and Andrew Warren stabbed Cornell-Duranleau more than 70 times on July 27, 2017. Prosecutors said Lathem paid Warren to travel to Chicago to commit the murder together.

Northwestern fired Lathem, a renowned microbiologist, after he fled the Chicago area following the killing.

Lathem testified at trial that Warren alone stabbed Cornell-Duranleau during what started as a methamphetamine-fueled sexual encounter involving the three men.

Warren pleaded guilty to murder in 2019. Under the plea deal, he agreed to testify against Lathem in exchange for receiving a 45-year prison sentence.

Warren, who was an Oxford University financial officer, testified that he flew from England to Chicago because he and Lathem had made a pact to kill each other, but then Lathem suggested they kill Cornell-Duranleau and he agreed.

He testified that he did stab Cornell-Duranleau, but only after Lathem had already begun stabbing him.