A few hours before six men were killed at a mosque in Quebec City on Jan. 29, U.S. President Donald Trump tweeted about how Christians are executed in the Middle East "in large numbers" and that an end must be put to the "horror."

Horror unfolded that Sunday night when a gunman arrived at the Centre Culturel Islamique de Québec and opened fire on the Muslim worshippers inside. In addition to the six men whose lives were cut short, 19 more were injured by the bullets.

The shocking attack did not prompt a tweet from Trump. It did prompt a phone call to Prime Minister Justin Trudeau the next morning, however, in which the president expressed his condolences.

"It's a terrible reminder of why we must remain vigilant and why the president is taking steps to be proactive rather than reactive when it comes to our nation's safety and security," White House press secretary Sean Spicer said at that day's briefing.

The mosque attack was two days after Trump signed an executive order that temporarily blocked refugees and citizens from seven Muslim-majority countries from entering the U.S. The president argued an "extreme vetting" system needs to be implemented to ensure terrorists aren't getting into the country.

Spicer pointed to Quebec City as evidence for why Trump's measures are needed, but the suspect in the case, Alexandre Bissonnette, is a Canadian-born citizen, not an immigrant or refugee. He is charged with six counts of first-degree murder and five counts of attempted murder while using a restricted firearm.

Little is known yet about the motives for the attack. Bissonnette was known to speak admiringly of Trump and the French far-right politician Marine Le Pen. He participated in a discussion group with fellow students at Laval University but found them too moderate for his liking, according to some members.

White House sad about loss of life

At the press briefing a few days later Spicer was asked what Trump is doing to prevent incidents of homegrown terrorism like the one in Quebec City. The reporter noted the suspect is a Canadian citizen.

Spicer seems to have missed the point of the question, because his response was that the "first thing is to make sure that we look at our borders" and that there is a "direct nexus between immigration and national security."

Spicer stumbled through the answer, saying that intelligence agencies also must look at cyberthreats.

White House press secretary Sean Spicer told reporters Jan. 30 that Trump called Prime Minister Justin Trudeau that morning to express condolences for the Quebec City mosque attack the night before. (Carolyn Kaster/Associated Press)

Spicer isn't the only one in the White House that has used the Quebec City attack as justification for Trump's travel ban, even though the suspect is Canadian.

Kellyanne Conway, one of Trump's top advisers, told CNN's Jake Tapper this week that the reason the president wants extreme vetting of immigrants and refugees is because of the threat of terrorist acts "not unlike the one that you're citing to our friends in the north."

Tapper brought up the mosque shooting in the context of Trump accusing media of purposely not reporting on terrorist attacks.

"In Quebec City last week, a white, right-wing terrorist opened fire on a mosque," said Tapper. "President Trump has not said or tweeted one public word about this. You want to talk about ignoring terrorism, why hasn't the president offered his sympathy to our neighbours in the north?" Tapper asked Conway.

In the days since the Quebec City attack, Trump tweeted, among many other things, about Arnold Schwarzenegger doing a poor job as host of his former show The Apprentice.

He also tweeted about an incident at the Louvre when a man approached soldiers with a machete and reportedly shouted "God is great" in Arabic. He was shot and taken into custody.

Trump 'doesn't tweet about everything'

"A new radical Islamic terrorist has just attacked in Louvre Museum in Paris. Tourists were locked down. France on edge again. GET SMART U.S," Trump wrote.

Why no tweet about six Muslim Canadians murdered, Tapper pressed Conway.

"He doesn't tweet about everything, he doesn't make a comment about everything," she said. Conway said Trump is "sympathetic to any loss of life," and that the White House is "sad" about what happened.

Tapper noted that a list the White House issued of under-reported attacks did not include any white, non-Muslim suspects, such as Bissonnette.

"Are these victims any less dead than the ones killed by Islamic radical terrorists?" he asked.

When she was asked about Trump's response to the Quebec City mosque attack, Kellyanne Conway told CNN that he is sympathetic about any loss of life. (Charles Krupa/Associated Press)

"No not at all," she responded and then went on to defend the president's travel ban.

Martha Crenshaw, a senior fellow at the Center for International Security and Cooperation at Stanford University, said it's strange that Trump's spokespeople are using Quebec City to justify the travel ban, given who the victims and suspect are.

"There is a disconnect that is difficult to explain," she said. "This example is exactly the opposite of the case you are trying to make about where the threat comes from."

Most attacks in recent years on American soil have been carried out by legal American residents, said Crenshaw, who has studied terrorism for 30 years.

Homegrown terrorism threat

Stephanie Carvin, an associate professor of international relations at the Norman Paterson School of International Affairs at Carleton University in Ottawa, also said that trends in terrorism increasingly indicate it is homegrown.

"It's an inconvenient truth, not to quote Al Gore, but it's an inconvenient fact," said Carvin.

Trump is focused on threats from outside the country, which are also real she said, and putting a spotlight on the Quebec City attack would perhaps undermine his case for the travel ban.

"If it had been an attack by an al-Qaeda or Islamist state-inspired extremist, we'd be hearing more about that from him," said Carvin, who added she's not surprised Trump didn't weigh in on Twitter about it.

Crenshaw said if you believe that Trump is strategic about what he tweets about and what he doesn't then yes, Carvin's theory could be plausible.

"One would say you just want to ignore facts that don't confirm what you already believe, so you just don't mention them."

It's also possible, however, that Trump has a short attention span and after calling Trudeau, moved on to something else, she said.