WARREN, Maine — Maine State Police are investigating the severe beating of an inmate at the Maine State Prison who is serving a life sentence for double murder.

Lloyd Franklin Millett, who was 35 in November 1995 when he murdered two women in Lewiston and Turner, was beaten by at least one other inmate on May 24 and taken to Eastern Maine Medical Center in Bangor. A spokeswoman for the hospital said Friday that Millett is in critical condition.

Maine Department of Public Safety spokesman Stephen McCausland said a team of detectives led by Sgt. Erik Baker has been working the case since the assault but has yet to press any charges. McCausland said the detectives’ report would be forwarded to the Knox County district attorney, who ultimately will decide how to move forward with the case.

Because the investigation is ongoing, McCausland declined to provide many details. He said it is normal for state police to investigate “all assaults of a serious nature” that occur within the prison system.

“The extent of Mr. Millett’s injuries and how the assault took place are things we won’t talk about at this point,” said McCausland, who also declined to say how many inmates were involved in the assault. He did say that no guards or prison employees are suspected in the beating.

Jody Breton, an associate commissioner for the Maine Department of Corrections, confirmed that there was an assault in the prison on May 24 but would discuss few other details. She would not answer questions about the extent of Millett’s injuries.

“Under the law I don’t believe I’m at liberty to discuss his medical condition,” said Breton. “I also can’t discuss any details around the investigation.”

Millett was convicted of killing two women over the course of a weekend in early November 1995 while he was a farmhand in Turner. According to Bangor Daily News archives, the victims were Terrie Lizotte, 39, of Canton and Rachelle Anne Williams, 33, of Gorham, N.H.

Williams’ body was found Nov. 6, 1995, in a field near the Ramada Inn in Lewiston, where she was attending a business meeting. She was last seen alive in a hotel lounge but disappeared after she left to go to a restroom and never returned. Williams’ raped and strangled body was found the next day.

Millett met his other victim, Lizotte, at a Turner nightclub on Nov. 3, 1995. He took her home and had consensual sex with her before killing her, according to the BDN’s archives. Lizotte’s body was found by Millett’s ex-girlfriend, who recently had moved out of his home but returned to retrieve her belongings.

Millett, a native of Rumford, pleaded guilty to both murders at one point in the case, though he later had a motion to reverse his pleas denied by the court. He was sentenced to 70 years in prison for Lizotte’s murder and a concurrent life sentence for killing Williams.

Millett had a lengthy criminal record before the murders, including a 1991 rape conviction for which he was sentenced to eight years in prison with four years suspended.