PORTAGE, Mich. (WOOD) — Investigators say the death of an elderly man in Portage that was already being investigated as suspicious was a homicide.

Police on Tuesday identified the man killed as Dr. Thomas Aye, 82. Aye was a retired oral surgeon with about 30 years of experience in the Kalamazoo area.

While they said a medical examiner had ruled his death a homicide, they did not say in a release how he died.

Emergency responders found Aye dead around 7 p.m. Sunday after being called to his home on Glencove Court off of Swan Creek Drive on a report of a man who was unresponsive.

The Portage Department of Public Safety on Monday said they had found evidence at the scene “indicating signs of violence,” but have so far not said exactly what that evidence was.

“We’re so early on in the investigation that we don’t know what’s important and what’s not important, so I want to be sure I’m careful with what I put out so that I don’t cause issues for the investigation,” Director of Portage Public Safety Nick Armold said. “From what I know about it so far, it definitely looks like it will be a unique case.”

Police say there have been no arrests.

Crews returned to the home Tuesday to investigate.

— News 8’s Jacqueline Francis contributed to this report.