The incident happened Monday when police were called to the Quality Inn on Vineyard Avenue for a woman yelling for help.
Ontario police say when officers arrived, they found a woman who had been injured in one of the rooms, with a man present.
The exact details of what happened next are still under investigation, but officers shot the man and he was later pronounced dead.
The woman was brought to a local hospital to be treated for the injuries she had prior to officers' arrival.
No officers were injured.
It's unknown if the man was armed.