SIOUX FALLS, S.D. — Sioux Falls police say they’re investigating a suspicious death reported last week at a Sioux Falls nursing home.

The Argus Leader says the incident happened on Thursday. Police Lt. Mike Colwill says a staff member at Southridge Healthcare heard what sounded like a body hitting the floor in the facility’s locked dementia unit.

Colwill says the staff member found a 78-year-old man standing over an 83-year-old woman, who had a visible head injury. The woman was transported to a local hospital, where she was diagnosed with a skull fracture and brain injury.

The woman died in a hospice unit on Sunday. Autopsy results are expected within a month.

Colwill said the man had a history of assaulting staff and other residents, and he may face charges.

Information from: Argus Leader,