As Hillary Clinton spoke at a campaign event in August in Kissimmee, Florida, just south of Orlando, where 49 people were killed in a mass shooting in June, a news agency noticed a man standing in the crowd behind the Democratic nominee.
That man was Seddique Mateen, the father of Pulse nightclub shooter Omar Mateen, who was killed by a SWAT team on June 12.
WPTV approached Mateen after the rally and asked him how Clinton's tribute to the Orlando victims affected him.
Popular VideoThis young teenage singer was shocked when Keith Urban invited her on stage at his concert. A few moments later, he made her wildest dreams come true.
"We've been cooperating with the federal government, and that's about it. Thank you," he said.
He reportedly refused to say anything further. However, WPTV reporters ran into him later on at a rest stop, and at that point Mateen was more forthcoming.
"Hillary Clinton is good for the United States versus Donald Trump, who has no solutions," he said.
Popular VideoThis young teenage singer was shocked when Keith Urban invited her on stage at his concert. A few moments later, he made her wildest dreams come true:
He was asked why he decided to attend the rally, given that it was so close to the site of his son's shooting rampage.
"I spoke a lot about that and wish that my son joined the Army and fought ISIS," he said. "That would be much better."
WPTV then inquired as to whether Mrs. Clinton's campaign was aware of his attendance.
"It's a democratic party, so everyone can join," he said.
When asked if he thought people might be surprised to learn of his presence, Mateen said that they had no reason to be.
"Why should they be surprised?" he asked. "I love the United States, and I've been living here a long time."
In a statement, a Clinton campaign official explained that the event was open to the public and that Mateen had not been personally invited.
"The rally was a 3,000-person, open-door event for the public," the statement said. "This individual wasn't invited as a guest and the campaign was unaware of his attendance until after the event."
In the immediate aftermath of the shooting, Mateen expressed regret for his son's actions, which he said he did not understand.
"He had a child and a wife and was very dignified, meaning he had respect for his parents," he said in a Facebook video, according to The Washington Post. "I don't know what caused him to shoot last night."
Mateen also addressed the families of the victims.
"If they're not ready, I still say to them, 'I'm sorry,'" he said. "I'm saddened for their injury or if they lost their dear one."
Prior to the shooting, Mateen appeared in a number of YouTube videos, in which he presents himself as an Afghani politician and expresses solidarity with the Taliban.
"People would make jokes of this guy, especially after videos surfaced of him claiming to be the president in exile," a senior Afghan government official told The Washington Post. "He looked very serious, but no one could tell what he was talking about."