Police have charged a man with second-degree murder in the death of an elderly nun who was found beaten to death at an east-end Montreal convent Monday morning.

Sister Estelle Lauzon, 81, had been helping her attacker at the convent's outreach centre when the attack occurred, police believe.

The outreach centre at the Sisters of Providence convent was home to troubled people who needed help to reintegrate into society.

Salvatore Mascia, lawyer for the accused, said his client, who has a psychiatric condition, had been living at the centre for about a year.

"It is a serious medical condition that requires medication," Mascia said. "All I can tell you for now is that medication is prescribed for him. Whether or not he took that medication, I really can't tell you at the moment."

Mascia also says his client is a recovering drug user and had been seeing a doctor for his psychiatric problem.

Martin Rondeau, 31, will be detained until his next court appearance on Sept. 24.