By Robert Moore, ITV News Washington Correspondent
This morning Canadians are coming to terms with yesterday's shocking assault on their Parliament.
They are also learning disturbing facts about the man responsible.
32 year-old Michael Zehaf-Bibeau was a recent convert to Islam. His father is a Libyan who fought Colonel Gaddafi. His mother is a senior Canadian immigration official.
He was known to police as a petty criminal who might harbour a much deeper and darker secret.
Whether Zehaf-Bibeau was a jihadist lone wolf loyal to the Islamic State is not yet clear. But he was certainly on the radar of counter-terrorism authorities in Canada.
His passport had been confiscated for fear he would join the Islamic State in Syria or Iraq.
Now we know he was a ticking time bomb, and that without a passport he would only end up striking much closer to home.
It raises an alarming question that will disturb British counter-terorrism officials.
By confiscating the passports of potential jihadists, and in the absence of effective de-radicalisation programmes, is the UK only increasing the chances of homegrown attacks from alienated extremists?
Last night, the Canadian Prime Minister told the world that his country would not be intimidated.
That may be true. Ottawa's support for the war on ISIS will be reinforced.
But Canada has been changed: There is a sense that Canada's innocence has been stolen.
It is a recognition that in this age of international terrorism, borders and oceans cannot keep you safe.
In many ways, what happened yesterday was not a surprise. Officials in many Western capitals have been warning of precisely such a low-tech, high-visibility, jihadi-inspired attack.
But no-one expected it here. Not in this tranquil capital.
Maybe that is what the killer wanted to show: That nowhere is out of reach, that no city is safe.