Michael Ford, 50, was removed from life support in Beaumont Hospital, The Detroit News reported. Police said he fell and hit his head after an officer used a Taser on him.
Ewayne Harrell said Ford had injuries that could not be explained by that version of events.
"He had a ruptured spleen, a cracked pelvis and cracks in the front and back of his head. I don't see how you can get all that from a Taser," Harrell said.
Officers used a Taser on Ford in the early morning hours of Aug. 14. One Livonia police officer said when he responded to a complaint about loud music in an apartment complex he found Ford in the parking lot holding a kitchen knife.
Ford refused to drop the weapon, the officer said.
"This was a deadly force situation and when there's no compliance to drop the weapon, the officer uses a Taser; it's better than shooting his gun," Deputy Police Chief Curtis Caid said Tuesday.