Constables Alain Diallo and Anne-Marie Dicaire just happened to be at Montreal's Dawson College last Sept. 13 on an unrelated call, when a tall man dressed in a black trench coat started firing at students.
"I screamed at him, I said, 'Police! Drop your weapon! Drop your weapon!'" said Diallo, who had only been on the job for one month.
The constables ran toward Gill and managed to corner him in the school's cafeteria.
"I could tell some students didn't realize what was going on. I had to yell for them to get out," Dicaire told CTV Montreal.
Montreal Deputy Police Chief Jean-Guy Gagnon was the senior officer in charge that day, when Gill killed one person and injured 20 others in a terrorizing shooting spree at the picturesque downtown college campus.
Gagnon told the Canadian Press on Wednesday the incident was the first real-time test of the city's emergency response plan, designed to deal with potential terrorist attacks following 9-11. And he said it worked well.
"We can see a big evolution from the polytechnique event to the Dawson event," Gagnon said.
"The first responder applied exactly to our training program."
After the Ecole polytechnique shooting in 1989, police officers were trained to identify and isolate the suspect or source of danger.
For 18 minutes on Sept. 13, police officers kept the heavily armed Gill pinned in that cafeteria, allowing many Dawson students to escape.
After the call went out for backup, Sgt. Martin Dea was the first to arrive on the scene.
"In the chaos, we tried to save as many lives as we could while dodging bullets." Dea told 麻豆影视. "The idea was as long as Gill is shooting at cops, he's not shooting at students."
For six long, harrowing minutes, they were alone, until Constables Marco Barcarolo and Denis Cote arrived. Barcarolo said he ran up the stairs, spotted Gil and saw a chance to shoot. But the adrenaline rush was taking its toll.
"I didn't have the ability to (take) a precise shot, and I wanted a precise shot because there were students on the same floor of the shooter," Barcarolo told 麻豆影视. "So instead of shooting, I just yelled at him to get his attention and he started shooting at me."
Cote briefly covered Barcarolo. He too was dodging bullets, until Gill's gun briefly went silent.
"He was forcing hostages to be his human shield," Cote said. Then, he finally saw an opening. For the first time in 22 years as a police officer, he opened fire.
A bullet struck Gill in the elbow and he dropped his gun. Seconds later, he would take his own life.
The officers said just like that, it was over. But a year later, they admit the tragedy had a profound impact on them.
"Emotionally, I still live with the situation. Everyday I think about the event," said Diallo. "There is not a day I'm not thinking about the victims of the event itself."
Gagnon applauded officers for their courage and teamwork as they went into the unknown, relying heavily on their instincts, intelligence and training.
He also lauded the work of ambulance technicians and doctors at Montreal General Hospital, who all helped limit the amount of blood shed that day.
"This is the reason we only have one death," Gagnon said.
Anastasia De Sousa, an 18-year-old student, was killed, and 20 other people were injured in the carnage. A memorial is to be held at the college on Thursday.
With reports from CTV's Jed Kahane, Stephane Giroux and The Canadian Press
