SUFFIELD, Conn. (WTNH) – George Legere, who in late September was arrested and charged in connection to the 1973 murder of a Connecticut woman, was declared dead after being found unresponsive in his cell last week.

Staff members at the MacDougall-Walker Correctional Institution in Suffield, Connecticut, responded to 77-year-old Legere’s cell at around 11 p.m. on Friday and found him unresponsive, according to the state’s department of corrections. Facility staff immediately began life-saving measures and Legere was taken to a local hospital, where he was pronounced dead early on Saturday morning.

The Office of the Chief Medical Examiner said the cause of Legere’s death is “pending further study.” The Connecticut Department of Correction and Connecticut State Police are investigating.

Legere, who was already serving a 25-year sentence in another cold case for kidnapping and sexual assault, was arrested Sept. 24 in connection with the murder of 21-year-old Janet Couture in 1973. Police charged him with murder after he confessed to fatally stabbing Couture in her East Hartford apartment while trying to steal money for drugs, according to an arrest warrant affidavit.

“I went into the apartment looking for money and unfortunately the person woke up and recognized me and that left me no choice to do what I did,” Legere said, according to police. “I ended up stabbing her.”

Investigators said Legere’s confession followed information from another inmate, who told police Legere admitted killing Couture and had written and signed a confession in July, instructing the inmate not to release it until after his death.

Police said Legere was an early suspect in Couture’s killing, but there was not enough evidence to charge him back in the 1970s.

“It was just such a shock because it’s been so long, you know, and we’ve always wanted it resolved and to know who did it,” Couture’s sister, Shirline Couture, said in a phone interview with the Associated Press last month. “I feel bad because my parents died not knowing. That was my mom’s last wish before she died.”

The Associated Press contributed to this report.