Rumours and emotions are running high after one police officer shot another at a rural crossroads in Pelham, Ont., according to the mayor of the town.

"There's lots of questions, but there's lots of emotion as well behind those questions," said Dave Augustyn. "I just hope they can get to the bottom of this and figure this out and provide healing. This will have ripple effects."

The mostly rural Pelham is southwest of St. Catharines.

Ontario's Special Investigations Unit (SIU) on Friday released more details, including that only one officer fired his weapon, and shot multiple times.

The shooter and the victim were among a group of officers in the area of Roland Road and Effingham Street investigating a collision that had occurred a few days before.

"One officer discharged his firearm multiple times, and the other officer was struck," an SIU news release said. "The officer who was struck was transported to hospital where he is in stable condition."

What would lead to individuals who are to serve and protect to turn on themselves. - Dave Augustyn , Pelham mayor

The release did not indicate how many times the victim was hit.

The SIU says it will not disclose the identities of the officers as per its policy while the investigation is ongoing. But Niagara police say the injured officer has 28 years of experience and is assigned to uniform patrol in Welland and Pelham.

Investigators work at the rural intersection of Roland Road and Effingham Street in the Town of Pelham. (Samantha Craggs/CBC)

There are 12 witness officers to what happened, including the man who was shot, according to the SIU.

It will not disclose the identities of those officers as per its policy while the investigation is ongoing. It also hasn't disclosed what led to the shooting or any specifics about the relationship between the two men.

"Understanding what transpired and the relationship between the officers is part of the SIU's investigation," spokesperson Monica Hudon said Thursday.

Union supporting both officers

Augustyn said there are plenty of rumours swirling about what happened.

"Our community is one where these types of things don't happen that often," he said. "The community is really just wondering what happened, and what would lead to individuals who are to serve and protect to turn on themselves."

The Niagara Regional Police Association, meanwhile, has heard from police services across the country, said president Cliff Priest. His association is supporting both officers and their families.

"When they hear about traumatic incidents involving police officers, it has a traumatic effect," he said. "This is our family. When one of our family hurts, we all hurt."

No arrests made

That support, he said, includes offering counselling, transportation or just listening.

Niagara Region Police Service Chief Bryan MacCulloch said he has asked the Ontario Provincial Police to determine if there is any criminal culpability outside the SIU's scope, but said no arrests have been made in connection with the shooting.

"The days and weeks ahead will be trying ones for the NRPS family and the community we serve," he said. "I ask for your support for our members and all those involved."

Kevin Bryan, a retired York police detective and policing instructor at Seneca College, says while conflicts between officers aren't unusual, he's never seen an incident like the one this week.

To have one police officer shoot another while on duty and in broad daylight is simply shocking, he said.

'For it to come to this, wow'

"I've seen infidelity on the job between officers and officer's spouses, where one officer is with somebody else's partner," said Bryan.

There'll be some choosing sides and stuff like that. - Kevin Bryan, policing instructor

"I know of incidents where someone has been punched in the face and stuff like that, over infidelity or perceived infidelity. But I've never seen it where it's come to shots — and on duty, too.

"I've seen an officer grab another officer by the shirt collar and push them up against a locker where one officer doesn't like another … but for it to come to this, wow."

And just like the shooting is having an impact on the community, it will ripple through the service as well.

"There'll be some choosing sides and stuff like that," Bryan said.

"There's going to be guys who maybe thought the guy deserved to be shot, and there's going to be guys who hated the [shooter]."

Bryan said that undoubtedly, NRPS higher ups are delving into the situation today to see if people were aware of any acrimony between the two officers.

Bryan said the while the situation is highly unusual, police unions have handled situations where they support officers in conflict.

"That can happen. It's awkward, but you just get them their own lawyers."

Michael Kempa, the chair of the department of criminology at the University of Ottawa, told CBC News that in a case like this, an officer would not be charged until the investigation is complete, which is the opposite of how it would generally go for a member of the public.

"I think the public would be surprised to know that for an ordinary police officer, the default would be not to begin with a charge, because we would assume at first that probably the discharge of the firearm was reasonable, and then we'll investigate and if we find something wrong, we'll then lay a charge … for a member of the public, it's the other way around," Kempa said.

But for a civilian, he said, "we say OK, a firearm was discharged, it's probably unreasonable, we'll lay the charge and then we'll see if we've got enough to secure a conviction."