Following a massive manhunt, RCMP found the suspected shooter a few kilometres away, dead inside a home.
"It appears the suspect forced entry into the residence but there was nobody home," RCMP Assistant Commissioner Marlin Degrand told reporters Saturday afternoon.
"When police found the suspect, he was dead."
Const. David Matthew Wynn, 42, is in grave condition, while Const. Derek Walter Bond, 49, was released from hospital Saturday evening.
Degrand said Bond is an auxiliary officer and would not have been armed with a gun. He normally carries pepper spray and a baton.
He has been volunteering with the force since 2008. Wynn joined the RCMP in 2009.
Degrand said Wynn's condition is dire.
"Definitely we are very concerned for his survival."
Investigators have tentatively identified the suspect, he said, but are waiting to confirm that information before releasing it.
Evidence suggests no one else was involved in the shooting, Degrand said.
The drama unfolded in St. Albert, an affluent community of about 60,000 bordering Edmonton's city limits to the northwest where the RCMP handles local policing.
Degrand said a fairly routine investigation into a suspicious vehicle led the two officers to the Apex Casino in an industrial area in the southeast end of the city at about 3 a.m. Saturday. The business was set to close at that time but Degrand said it was still open when the officers walked inside.
They had determined the vehicle was stolen and were looking for suspects, he said.
It didn't appear the officers were expecting trouble when they walked inside, Degrand said. The suspect fired two shots and the one officer who had a gun didn't get a chance to use it.
Degrand wouldn't reveal more details about what happened inside the casino but said investigators seized security video footage from the business.
Police next tracked the suspect to a rural area near the Sturgeon Valley Golf Course, not far from the shooting scene.
They blocked off several roads as they searched and a helicopter flew overhead. They warned people to stay away from the area and said they believed their suspect armed and dangerous.
The roads were opened about 13 hours later, shortly after word came that the suspect had been located.
Investigators seemed to be focusing their attention on a home on an acreage in a rural neighbourhood called Sturgeon Heights. Police had blocked access to the property and it appeared the front door of the home had been forced open.
A dark-coloured pickup truck left partly in the ditch, not far from the home, was hauled away from the scene.
Degrand said officers spent some time containing the property before they felt it was safe to go inside and attempt an arrest. When they did enter, they found the suspect's body.
"At no time during these efforts to arrest the suspect at that residence did officers speak with the suspect or fire their weapons," he said.
Neighbour Ted Elkins said he wife woke him at 5 a.m. when she heard a chopper overhead.
"It's very sad. It's terrible, you know. They are investigating a stolen vehicle and next thing you know they are fighting for their lives," Elkins said. "It's very hard on families so you grieve with them too."
He said the home was owned by a quiet couple in their 70s.
Another resident in the area, Larry Martin, said he didn't hear anything out of the ordinary early Saturday and didn't know anything was going on until he saw police when he went out to get his newspaper.
He said he's glad the Mounties found the suspect.
"If he is no longer with us, I don't have a problem with that," Martin said. "Our courts are far too lenient for some of these guys."
Degrand said the man believed to be the shooter is known to police.
He said the shooting should remind everyone of the dangers first-responders face in the line of duty. "Our thoughts are with our injured officers and their loved ones and our colleagues who are courageously pursuing this investigation."
Prime Minister Stephen Harper released a statement on Twitter expressing his concern.
"Canada's thoughts and prayers are with (Alberta RCMP) officers today," the tweet read.
Alberta Premier Jim Prentice also released a statement, saying he was shocked and saddened by the shooting of officers while in the line of duty.
— With Tim Cook and Rob Drinkwater in Edmonton