Seddique Mir Mateen, the father of the man blamed for the Orlando nightclub massacre, attended Hillary Clinton's campaign rally in Kissimmee, Florida, Monday. He's seen in video sitting in the crowd behind Clinton on stage.
His son Omar Mateen, 29, killed 49 people and wounded dozens of others in the worst mass shooting in recent U.S. history.
The Clinton campaign said today in a statement: "The rally was a 3,000-person, open-door event for the public. This individual wasn't invited as a guest and the campaign was unaware of his attendance until after the event."
The event was held not far from the site of the mass shooting.
Omar Mateen opened fire on the Pulse nightclub, a popular spot for the LGBT community, on June 12 and pledged allegiance to ISIS during a 911 call. He was killed in a gun battle with cops.
Clinton visited a memorial outside Pulse nightclub last month during a trip to Orlando, where she held a roundtable to discuss gun violence.