So far, there have been no arrests but an internal investigation is underway.
The incident happened in the parking lot Saturday night when comedian Kevin Hart was about to start his second performance of the evening.
"An altercation (turned) ugly," said police Lt. Jill McDonnell. " Traffic was quite heavy because of the back to back shows."
McDonnell said that's where an off-duty detroit police officer was changing a tire when a man and woman tried to back into the spot right next to him, leading to an argument. The 26-year-old officer sustained a head injury in the scuffle that ensued - he then grabbed his gun.
"That verbal altercation turned physical and then there were shots fired," McDonnell said. "It appears he fired some shots and two people were struck by the bullets."
A 32-year-old man from Detroit and his 31-year-old female companion from Harper Woods were both wounded.
All three people were taken to the hospital. The officer and the woman were treated and released - the other man was still hospitalized Sunday but expected to be okay. no one was arrested.
All parties were interviewed and released pending the outcome of the investigation.