"So I heard a sound that, unfortunately, is all too familiar. So I knew something was wrong right away," Fitzpatrick said.
Fitzpatrick's fiancée, Fox News correspondent Jacqui Heinrich, had been seated at the head table alongside members of the Trump administration, including Vice President JD Vance. Video released by the administration appeared to show the suspect sprinting past a security checkpoint before shots were fired.
"It's in a nanosecond, you saw how fast he was running. But thankfully, they did their job, and they were able to apprehend him," Fitzpatrick said.
The congressman said he and thousands of other attendees remained inside the ballroom until law enforcement declared the area secure. He said his only focus in the moment was Heinrich's safety.
"Honestly, I was concerned about Jacqui. She was at the head table; that was all I cared about. I tried to get back, but the Secret Service assured me that she was okay," he said.
Fitzpatrick, a 15-year veteran of the FBI, said the incident raises questions about holding high-profile events in hotels, where security screening areas are often located deep within the building.
"Unlike a lot of other venues, sporting events, for example, the security and the magnetometers are well into the interior of the facility, but outside the event," he said. "You have people that are not part of the event, not credentialed, not screened, but yet still in the building."
President Trump has said he plans to reschedule the dinner within the next 30 days, though a venue has not yet been announced.
Fitzpatrick said the incident reflects a broader issue in today's political climate.
"It's just sadness in general that things have gotten to the point where people are resorting to violence," he said. "We can't allow that to happen."