The mother of the man accused of killing a soldier at Ottawa’s war memorial before storming parliament and being shot dead says she is mourning the victims of the shooting, not her son.

• Canada parliament attack: eyewitness account

In a brief and tear-filled telephone interview with The Associated Press on Thursday, Susan Bibeau said she did not know what to say to those hurt in the attack.

“Can you ever explain something like this?” she said. “We are sorry.”

Investigators offered little information about the gunman in Ottawa, identified as 32-year-old petty criminal Michael Zehaf-Bibeau.

Canadian police conceded on Thursday that Zehaf-Bibeau was the lone gunman, the second attack in three days in what the prime minister described as terrorism.

Bibeau said she was devastated for the victims of the attack.

Alleged gunman Michael Zehaf-Bibeau.

“If I’m crying it’s for the people,” she said, struggling to hold back tears. “Not for my son.”

Bibeau and her husband had earlier sent the AP a lengthy email expressing horror and sadness at what happened.

“I am mad at my son,” the email said, explaining that he seemed lost “and did not fit in.”

“I his mother spoke with him last week over lunch, I had not seen him for over five years before that,” the email said. “So I have very little insight to offer.”

Government officials credited 58-year-old Parliament sergeant-at-arms Kevin Vickers with shooting the attacker just outside the MPs’ caucus rooms.

MPs gave Vickers a rousing standing ovation for saving their lives as parliament resumed on Thursday morning.

Court records that appear to be the gunman’s show that he had a long rap sheet, with a string of convictions for assault, robbery, drug and weapons offences, and other crimes.