OTTAWA — The story of three heroic Ottawa paramedics and their role in apprehending Kevin Gregson on the night he fatally stabbed Ottawa Const. Eric Czapnik has been closely guarded for more than two years.

It was finally told Wednesday to a packed Ottawa courtroom where the 45-year-old former Mountie is standing trial for first-degree murder.

The early hours of a freezing Dec. 29, 2009, had been routine for veteran paramedic Craig McInnes and his colleagues, Amanda Walkowiak and Patricia St. Denis.

They had been chatting and completing paperwork in their “write-up room” overlooking the ambulance bay of The Ottawa Hospital’s Civic campus at about 3:40 a.m. when MacInnes noticed a car pull in.

“I didn’t think anything of it,” he told the court. “It didn’t seem like a dangerous situation.”

Then all hell broke loose and the ensuing minutes would seem like an eternity.

“What’s that officer doing trying to do? Arrest that man?” said Walkowiak. “Is he trying to take him down?”

MacInnes, a paramedic for 24 years, jumped to his feet and sprinted out into the parking lot, with Walkowiak and St. Denis close behind.

“I wanted to see if our assistance was needed,” he said.

MacInnes rounded a police cruiser where earlier he had noticed an officer writing a report.

That officer, Czapnik, was pinned beneath Gregson on the frozen ground. Both were big men.

Gregson was using his knees to restrain Czapnik and, said MacInnes, was making short, punching, rapid-fire motions — perhaps six to 10 punches.

“I was confused and shocked,” he said. “It’s difficult to describe.”

MacInnes pounced onto Gregson’s back, locked his arms around the man’s neck and yanked him off the police officer.

Czapnik’s jugular had been slashed and blood was bubbling from his neck. As the paramedic pulled Gregson from him, Czapnik struggled to his feet, unable to speak.

“He looked at me in disbelief with big, bulging eyes,” MacInnes said.

Walkowiak, close behind, saw Czapnik with one hand on his throat and the other on his gun.

“He had a look of disbelief. I’ve never seen eyes so wide.” She urged him to get to the emergency room. The paramedics sensed he wanted to stay and help.

Before staggering toward the emergency door, his eyes met those of Patricia St. Denis.

“He mouthed ‘thank you’ to me,” said an emotional St. Denis. “He couldn’t speak.”

During that brief flash of time, the three paramedics described, MacInnes had Gregson pinned to the ground, lying alongside the accused murderer almost face to face.

In one of a string of split-second, surreal moments, the paramedic said he asked Gregson why he had attacked Czapnik.

“All he had to do was give up his gun,” Gregson told him. “It didn’t have to end this way. All he had to do was give me his gun.”

MacInnes told the court that he responded: “No police officer ever gives up his gun.”

Walkowiak screamed that Gregson was still holding a knife and felt sure it was headed toward her colleague’s face.