Ministers and lawmakers identified the House of Commons' sergeant-at-arms, Kevin Vickers, as the man responsible for firing the shots that brought down the assailant, identified as Muslim convert Michael Zehaf-Bibeau.
Mr Vickers, a 29-year veteran of the Royal Canadian Mounted Police, was appointed sergeant-at-arms in 2006.

He also carries the mace, the symbol of parliamentary authority, during formal proceedings and ceremonies.
Member of parliament Craig Scott said on Twitter that Mr Vickers had shot the gunman just as he approached rooms packed with politicians.
Senator Linda Frum responded to a tweet identifying Mr Vickers as the man who had brought the shootout to a bloody conclusion with one word: "Hero."
Several journalists also praised Mr Vickers, with CTV News broadcaster Mercedes Stephenson remarking: "Heroic actions by sergeant-at-arms Kevin Vickers today. He saved lives."
CBC reporter Kady O'Malley said: "Remind me to hug Kevin Vickers next time I see him."
The gunman has been identified as Michael Zehaf-Bibeau, a Muslim convert who was born Michael Joseph Hall, who reportedly fought in Libya during the uprising which deposed strongman Moamar Gaddafi.
He was shot dead by the parliament's sergeant-at-arms, who has been hailed a hero by MPs who were caught in the building as dozens of shots were fired.
Soldier shot in chest while on guard duty
The violence began about 10:00am (local time) when a soldier Nathan Cirillo, a 24-year-old reservist serving with the Argyll and Sutherland Highlanders of Canada regiment, was shot in the chest with a rifle as he stood on guard.
It is believed that Zehaf-Bibeau then hijacked a car and ran into the nearby parliament building where he opened fire when confronted by security staff.
Pictures from inside the parliament showed MPs barricading themselves into a room as security guards traded fire with the gunman.
"I literally had just taken off my jacket to go into caucus. I hear this 'pop, pop, pop', possibly 10 shots," Liberal Party member John McKay told reporters.
"Suddenly the security guards come rushing down the hallways and usher us all out to the back of the parliament buildings."
Witnesses said they saw a man armed with a rifle running into parliament after the shooting at the war monument.
A construction worker on the scene said he heard a gunshot, then saw a man dressed in black with a scarf over his face running towards parliament with a gun.
The gunman rushed past a woman with a child in a stroller, who ran away screaming. He did not attack the woman or child, construction worker Scott Walsh told Reuters.
Another witness, Marc-Andre Viau, said he saw a man run into the parliament precinct, chased by police who yelled "take cover".
That was followed by "10, 15, maybe 20 shots", possibly from an automatic weapon, he said.
Veterans affairs minister Julian Fantino, a former policeman, said parliament's head of security, sergeant-at-arms Kevin Vickers, shot dead a suspected gunman.
"All the details are not in, but the sergeant-at-arms, a former Mountie, is the one that engaged the gunman, or one of them at least, and stopped this," Mr Fantino said.
Gunman had criminal record
Court documents reveal the 32-year-old Zehaf-Bibeau had served jail time in Quebec 10 years ago for drug-related charges.
He had recently converted to Islam and was also charged with robbery in 2011.

Canada announced this month it was joining the battle against Islamic State fighters who have taken over parts of Iraq and Syria.
Hours after the incident near Montreal, Canada raised its national terrorism threat level to medium because of a rise in "general chatter" from radical groups such as IS and Al Qaeda but said there had not been a specific threat.