CRANSTON, R.I. (WPRI) — A man suspected of killing a married couple in Lincoln last week has died, the Rhode Island Department of Corrections (RIDOC) confirms.

Timothy McQuesten, 49, was arrested Thursday and charged with the murders of Kimberly and Mark Dupre.

According to RIDOC spokesperson J.R. Ventura, correctional officers found McQuesten unresponsive Monday evening inside his cell at the ACI’s intake center. They performed life-saving measures before a rescue arrived to take McQuesten to Rhode Island Hospital, where he was later pronounced dead.

The cause of his death is being investigated, but Ventura said foul play is not suspected.

Lincoln police say they found the Dupres badly beaten inside their Main Street home Thursday morning. Kimberly was already dead, while Mark was suffering from serious injuries and died soon after at the hospital.

McQuesten called 911 a few hours later saying he was distressed about what happened to the Dupres, according to prosecutors. Police took McQuesten in for questioning after he used information specific to the case that had not yet been made public, prosecutors said, and detectives found bloody clothes and “a crowbar and hammer with what appeared to be blood on it” during a subsequent search of his home and vehicle.

A motive for the murders is currently unclear. Prosecutors say McQuesten knew Kimberly Dupre but the two hadn’t spoken in years, until he reached out on Wednesday. He sought to meet up with her, but she declined.