First a soldier guarding a hallowed war memorial was gunned down in Canada's capital. Then shots erupted in the halls of the country's Parliament minutes later.
The two shootings in Ottawa Wednesday left lawmakers barricaded inside offices and parts of the city on lockdown for hours as police searched for suspects.
Ottawa Police lifted the lockdown Wednesday night and said there was no longer a danger to the public.
But many questions remain about the shootings: Who was the gunman? Why did he open fire? And was he acting alone?
Why would three American teenage girls from Denver try to join ISIS?
We asked Mubin Shaikh, a former jihadist, to offer context – and he says the answer is a mix of a search for identity, adventure and a false sense of reality.
"You reinforce in yourself this idea that you can participate in something far greater than your mundane existence at home," Shaikh told CNN's Michaela Pereira.
Shaikh now works for Canada's intelligence service but says he can offer perspective on these teens because he once was a young Muslim who came to the edge of extremism.
He was brought back by a support network of parents, friends and religious elders.
"It will take a holistic effort and it can't be done by coercive forces," to reach vulnerable people who may consider extremism, Shaikh said.
In this Denver case, two families called the FBI and the teens were intercepted in Germany.
"It's better that your kid get arrested or at least talked to than be used as a sex slave," Shaikh said.
"A lot of them are living in a fantasy world and just don't understand what awaits them on the other side."
After five months of detention in North Korea, Jeffrey Fowle arrived home in Ohio early Wednesday for an emotional reunion with his family.
Stepping off the plane at Wright-Patterson Air Force Base and onto the tarmac, he was embraced by family members, including his three children.
"It's a good sign that the North Koreans released this man unconditionally," former U.S. Ambassador to the United Nations Bill Richardson told CNN's "New Day." "They usually demand a price."
Richardson has helped negotiate the release of prisoners in the past, including from North Korea.
Pyongyang's move is "a signal to the U.S. that says, 'All right, let's start talking,' " and perhaps restart nuclear negotiations, he said.
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