An Edmonton man charged in the fatal attack of a woman in a downtown seniors home pleaded guilty on Friday to manslaughter and sexual assault causing bodily harm.

Marvin Arthur Witzaney, 47, was originally charged with second-degree murder, aggravated sexual assault and break and enter after an 84-year-old woman was attacked in her suite at the Edmonton Chinese Seniors' Lodge on May 8, 2011.

The woman, whose name was subject to a court-ordered publication ban, died in hospital eight days later.

Marvin Witzaney, 47, pleaded guilty to attacking an 84-year-old woman in 2011. She died in hospital eight days after the assault.Marvin Witzaney, 47, pleaded guilty to attacking an 84-year-old woman in 2011. She died in hospital eight days after the assault. (CBC)

Witzaney also pleaded guilty on Friday to two counts of attempted break and enter.

According to an agreed statement of facts, Witzaney broke into the seniors' home twice the night the woman was attacked. He was scared away the first time. The second time he gained entry to the victim's suite.

He attacked the woman, smashed her in the back of the head with a stainless steel thermos and then sexually assaulted her.

The woman was able to push the panic button but Witzaney got away.

The court was told that Witzaney was obsessed with the Edmonton Chinese Seniors' Lodge. Since 2000, he had been the subject of numerous complaints about trespassing and committing indecent acts, the court document said.

A sentencing hearing is scheduled for April 15.

With files from CBC's Janice Johnston