A man who was sentenced to remain behind bars for the rest of his life after taking a guilty plea for killing Det. Kristen Hearne in 2017 was found dead on Thanksgiving, according to reporting from the Atlanta Journal-Constitution this week.

Per their reporting, Seth Brandon Spangler, who pleaded guilty earlier this year before facing a death penalty trial for Det. Hearne’s murder, was found dead by officials in his cell at the Augusta State Medical Prison.

Spangler prior to that was at the Telfair State Prison, where he was serving his sentence for life without the possibility of parole.

Per the AJC, Spangler’s attorney told reporters that he was transferred recently to the Medical Prison’s Crisis Management Unit, where he was on suicide watch at the time.

His death on Thanksgiving Day came despite the conditions he was placed under in the medical unit for the Department of Corrections.

Spangler had a history of mental illness prior to the ambush shooting death of Det. Hearne in September 2017.

The Department of Corrections confirmed the death to the AJC, but didn’t comment on the specifics since they reported Spangler’s death was still under investigation. The GBI Crime Lab took Spangler’s body for an autopsy.

Samantha Roof, the second defendant in the murder of Det. Hearne, took a guilty plea for involuntary manslaughter in lieu of facing a trial back in August.