A convicted killer imprisoned for hammering a woman and her child to death has been charged with second-degree murder in connection to a homicide at the Mission Institution in 2011.

James Saar is now charged in the death of fellow inmate Troy Robert Squires at Mission Institution on Dec. 2, 2011, said Integrated Homicide Investigation Team spokeswoman Sgt. Jennifer Pound.

Squires, 39, who was being held indefinitely at the prison as a dangerous offender, was found dead in his cell at 10:45 p.m.

The victim's injuries were consistent with the use of an edged weapon, said Pound.

Several suspects were arrested at the initial stages of the investigation but Saar was later identified as the suspect.

"Evidence retrieved by IHIT investigators led us to believe Mr. Saar was a suspect," said Pound.

"Further investigation and assistance by our forensics section provided further evidence to support and secure second degree murder charges."

Saar was serving a life sentence for murder and aggravated assault for the 1997 death of Karen Naytowhow and her eight-year-old daughter Lacey in Paddockwood, Sask.

The mother and daughter were hit multiple times in the head with a hammer and their bodies were also set on fire.

Two other girls in the home at the time of the attacks survived.

Saar was eligible for his first parole hearing in 2017.

After Squires' death, Saar was moved from Mission Institution to a maximum-security facility outside of B.C., said Pound.

The accused and the victim were not cellmates, she said.

When killed, Squires was serving time for numerous offences, including forcible confinement, sexual assault, uttering threats, choking to overcoming resistance and assault with a weapon after starting his sentence in January 2006.