The Niagara Regional Police Service now says one of its officers is listed in stable condition after being shot on Thursday afternoon by a fellow cop.
It happened around 12:15 in Pelham, southwest of St. Catherines at the site of a recent crash.
It's not clear what led to the altercation, but a 52-year-old officer with 28 years of experience was shot by another officer and airlifted to a Hamilton hospital in critical condition.
The force now says the officer is in stable condition as the Special Investigations Unit takes over the investigation.
"In the spirit of transparency, I have asked the Ontario Provincial Police to determine if there is any criminal culpability outside of the SIUs scope," NRPS Police Chief Bryan MacCulloch said in a statement. "At this point in time, no arrests have been made in relation to this incident."
"The days and weeks ahead will be trying ones for the NRPS family and the community we serve. I ask for your support for our members and all those involved."
The SIU has not confirmed how many shots were fired, but several media reports say there were multiple shots.