Singers Anthony Wong, left, and Denise Ho lay flowers during a candlelight vigil to mourn victims of the Pulse Orlando shooting, Hong Kong, China, June 13, 2016.
Man lights candles atop rainbow flag in solidarity with Pulse Orlando victims, Madrid, Spain, June 12, 2016.
Tel-Aviv city hall lit up with rainbow flag colors in solidarity with victims of Pulse Orlando shooting, Israel, June 12, 2016.
Candlelight vigil for victims of Pulse Orlando massacre, Seoul, South Korea, June 12, 2016.
Vigil for victims of Pulse Orlando shooting in front of the U.S. Embassy and Brandenburg gate, Berlin, Germany, June 13, 2016.
American flags, rainbow banners in tribute to victims of Pulse Orlando massacre, Paris, France, June 13, 2016.
People attend vigil at for Pulse Orlando victims of LGBTQ Center of Southern Nevada, in Las Vegas, June 12, 2016. (K. Farabaugh/VOA)
A candlelight vigil in memory of the victims of Pulse Orlando shooting at the U.S. Embassy in Bangkok, Thailand, June 13, 2016.
Memorial outside The Stonewall Inn, considered by many the center of New York's gay rights movement, following Pulse Orlando massacre, Manhattan, June 12, 2016.
People attend candlelight vigil for Pulse Orlando attack, at City Hall, San Francisco, California, June 12, 2016.
Man lights candle during vigil for victims of mass shooting at the Pulse Orlando nightclub, in front of U.S. embassy, Santiago, Chile, June 12, 2016.
Man looks over impromptu memorial for victims of Pulse Orlando massacre, Sydney, Australia, June 13, 2016.
As Americans mourn victims of the mass shooting over the weekend, authorities are focusing on what can be done to prevent “homegrown” extremist attacks.
Sunday's shooting at a popular gay nightclub killed 49 people and injured 53 others. It was the worst mass shooting in U.S. history.
The Federal Bureau of Investigation confirmed it had investigated the Orlando gunman, Omar Mateen, on suspicion of possible terrorist ties.
FBI Director James Comey told a news conference Monday the FBI conducted interviews with Mateen in 2013 and 2014. Investigators also followed him and reviewed details of some of his contacts and communications.
But authorities took no action against him because the FBI did not find any evidence of criminal activity. Comey said the FBI is currently reviewing its practices in the case. But at this point, he said he believes the agency acted appropriately.
Comey said the Orlando shooter had “strong indications of radicalization” and may have been “inspired by foreign terrorist organizations.”
But he added that the FBI has so far found no evidence indicating the gunman was assisted or supported by any terror groups outside of the United States.
After he was briefed by Comey, U.S. President Barack Obama told reporters at the White House the massacre appeared to be an example of “homegrown extremism.”
“At this stage, we see no clear evidence that he was directed externally. It does appear that at the last minute, he announced allegiance to ISIL (IS),” he added.
Mateen spoke with a 911 operator three times during the attack, according to Comey. He claimed allegiance to the leader of Islamic State. In the calls, Mateen also mentioned the Boston Marathon bombers and a man who carried out a suicide attack in Syria.
On Monday, the Islamic State radio called Mateen “one of the soldiers of the caliphate in America.” The broadcast on Al-Bayan Radio said the attack targeted Christians and gays. However, the terrorist group did not make any claim of responsibility for the attack.
A spokesman for Saudi Arabia's Interior Ministry told the Associated Press that Mateen had visited the kingdom twice in 2011 and 2012 for religious rites known as umrah pilgrimage. It is shorter than the annual hajj and can be performed any time.
Businessman Donald Trump is the presumptive Republican presidential nominee. Without mentioning the shooter's name, Trump renewed his call to ban Muslims from entering the U.S. Mateen, however, was born in the U.S. to Afghan parents.
Hillary Clinton, Trump's Democratic rival, said stopping “lone wolf” terrorists will be her top priority. The former secretary of state repeated her call for banning assault weapons. “I believe weapons of war have no place on our streets,” she said.
Difficulties in dealing with homegrown terrorism
National security experts say the FBI has a difficult task, with more than 1,000 active investigations in all 50 states of people suspected of having terrorism ties.
Seamus Hughes is the deputy director of the Program on Extremism at George Washington University. He says it is hard for investigators to know whether someone's thoughts and views will ever cause them to commit a violent act.
“The issue always becomes, when someone goes from radical thought to actual actions - and that's what the FBI is trying to grapple with right now.”
The shooting appears to have been a “lone wolf” attack, according to Tom Sanderson of the Centers for Strategic and International Studies.
Lone wolf attacks are usually inspired by extremist groups, but are carried out by individuals without direct support from terror organizations. Sanderson said these kinds of attacks are likely to continue.
“We've seen lone wolf actors in the past, we know they're out there. We know that the ISIS leader Baghdadi has called on them to attack whenever and wherever they can. So when one is able to do it, they will. And this is not the last attack, unfortunately.”
Professor R. Nicholas Palarino, from Georgetown University's Center for Security Studies, said authorities need to find better ways to counter rampant extremist ideology on the Internet.
“You do have to counter the ideology - especially the ideology that's spreading over social media, and the Internet. And then number two you have to demonstrate that the jihadist movement cannot win.”
I'm Bryan Lynn.
Bryan Lynn wrote this story based on reporting from Chris Hannas of VOA and additional reporting from the Associated Press. Hai Do was the editor.
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Words in This Story
appropriately - adj. correct and suited for a specific purpose
external - adj. coming from outside
allegiance - n. have loyalty to a person, country or group
grapple - v. to struggle with or work hard to overcome
radicalize - v. cause someone to adopt radical political and social views
rampant - adj. growing very quickly in a way that is hard to control
jihadist - adj. a Muslim who advocates of participates in jihad
