EDMONTON -- An Edmonton man admitted in court Friday to breaking into a seniors residence and sexually assaulting an 84-year-old woman who died as a result.

Marvin Arthur Witzaney, 47, pleaded guilty in Court of Queen's Bench to manslaughter, break, enter and commit sexual assault causing bodily harm, two counts of attempted break and enter and a breach of recognizance.

Court heard there will be a joint submission for a life sentence, but the Crown and defence will argue about how long Witzaney must serve before being eligible for parole.

According to an agreed statement of facts, Witzaney terrorized residents of the Edmonton Chinese Senior's Lodge between 2000 and 2008 and was repeatedly charged with trespassing and indecent acts.

Crown prosecutor Tania Holland said his photo had even been placed in the lodge to warn residents about him.

On May 8, 2011, about 2:20 a.m., Witzaney tried to break in to two suites at the lodge through windows, but was stymied when a 77-year-old man punched him in the face and then the senior and a housekeeper scared him away.

A police officer responded about 3 a.m. and noticed two smashed windows, but the officer cleared the investigation and left when he could not find a suspect.

Witzaney returned and broke into the suite of the 84-year-old victim by smashing a window. He then began sexually assaulting her.

The housekeeper responded to the suite after noting a distress alarm and found Witzaney on top of the senior.

She yelled at him and ran to get help and call police after locking the door.

When the lodge manager arrived, the room was unlocked and Witzaney had fled.

Court heard police arrived and found the victim naked from the waist down, lying in a pool of blood with two deep cuts on the back of her head.

She was taken to hospital with multiple traumatic injuries, including a brain injury that caused delirium.

She died eight days later. Her death was later linked to the brain injury.

An autopsy found she had blunt injuries across her body and more than 30 bruises. There were also two points of impact to the back of her skull, which the pathologist said could have been caused by blows from a stainless steel thermos that had Witzaney's prints on it.

Witzaney was arrested at his home with swollen hands on the evening of May 8, 2011, and was charged with second-degree murder following the death of the victim.

Justice Eric Macklin ordered a pre-sentence report and a psychiatric assessment on Witzaney and a sentencing hearing was scheduled for April 15.