Hillary Clinton hosted a campaign event Monday evening in Kissimmee, Florida.

But on Tuesday, the story became not so much about what Clinton said than about the presence of a man in a red hat sitting in the crowd behind her.

During her speech, the Democratic presidential hopeful spoke about the June 12 massacre at the Pulse nightclub in Orlando in which 49 people lost their lives and 53 others were wounded.

Sitting behind Clinton, among numerous other supporters, was the father of the Pulse gunman, Omar Mateen.

Seddique Mateen, who once ran for the presidency of Afghanistan, has denounced the actions of his son in Orlando.

During an interview in the days after the attack, Seddique Mateen went further, saying, "I cannot forgive him."

The Clinton campaign has not said whether any staffers knew that Mateen was planning to attend the rally.

Speaking after the event, Mateen said he believed in Clinton’s message and her plan for the U.S.

"Clinton is good for (the) United States vs. Donald Trump, who has no solutions," he told WPTV.

Mateen said he was invited to the event by the Democratic Party.

"I'm a member (of the Democratic Party), so as a member I get the invitations," he said. "Nothing particular about it."

When asked how he felt when Clinton mentioned the Pulse massacre, Mateen said he thought about what his son could have been and done, not what he did.

"I wish that my son joined the Army and fought ISIS and destroyed ISIS," Mateen said. "That would be much better."

Omar Mateen called 911 before and during the Pulse attack and declared allegiance to ISIS, police said.

Asked whether Clinton knew that he would be sitting directly behind her, Seddique Mateen brushed off the question.

"It"s a Democratic Party, so everybody can join," he said.

Mateen said people in and around Orlando should not be surprised to see him in the area.

"Why they should be surprised?" he asked. "I love (the) United States, and I've been living here a long time."

The Clinton campaign said Mateen "wasn't invited as a guest, and the campaign was unaware of his attendance until after the event."

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