The Pennsylvania State Police and the FBI held a joint press conference on the attempted assassination of former President Donald Trump shortly before midnight on Saturday.

Law enforcement officials called on witnesses, rallygoers and anyone with information on the shooting or the perpetrator to come forward and provide information. An FBI spokesman did not confirm whether the shooter had been identified, though law enforcement had earlier reported that the shooter was a 20-year-old male from the area.

“This evening we’ve had what we’re calling an assassination attempt against our former President Donald Trump,” an FBI special agent said during the press conference.

After law enforcement agencies had only referred to the shooting as an “incident” earlier in the day, the FBI confirmed that it was indeed an “assassination attempt.”

Police confirmed that the gunman was firing from a rooftop overlooking the venue. A spokesman for the agency revealed that the buildings were outside the security perimeter despite their close proximity to the venue.

Police also confirmed that they are following up on reports of “suspicious activity” in the moments and hours leading up to the shooting, including reports from witnesses who spotted the gunman prior to the shooting. While law enforcement officials confirmed that officers were responding to a “number of reports on suspicious activity,” they did not provide further detail

The FBI told reporters that they had not received reports of a credible threat leading up to the event.

A spokesman for the bureau also reported that they have not yet identified the gunman or established a motive, though they believe they are close to making that determination. They also did not disclose any information as to the weapon used by the gunman while they await DNA confirmation.

Law enforcement officials did not rule out the possibility that the gunman had help, though they do not believe there is a current threat associated with the incident at this time.

The New York Post reported that the gunman has been identified as Thomas Matthew Crooks, a 20-year-old male from Bethel Park, Pennsylvania.

According to the report, Crooks was killed by Secret Service snipers, who could be seen engaging the shooter as soon as he opened fire. An “AR-style rifle” was recovered from the scene.

This is a developing story.