The Federal Bureau of Investigation has identified 20-year-old Thomas Matthew Crooks as the "subject involved" in the attempted assassination of former President Donald Trump, according to a statement released on Sunday.

Former US President Donald Trump was seen descending the stairs of his aircraft upon landing in New Jersey early on Sunday, as shown in a video posted on the social media platform X by the Trump campaign. Trump, aged 78, had just commenced his speech when gunshots were heard. He instinctively reached for his right ear with his right hand, examined his hand, and then fell to his knees behind the podium as Secret Service agents swiftly surrounded and shielded him. Approximately a minute later, he reappeared, his red "Make America Great Again" hat dislodged, and could be heard instructing "wait, wait" before being escorted into a vehicle.

"I was struck by a bullet that penetrated the upper part of my right ear," Trump disclosed on his Truth Social platform following the incident in Butler, Pennsylvania, approximately 30 miles (50 km) north of Pittsburgh. "Significant bleeding occurred."

The shooter's identity and motives remained unclear at the time. Both prominent Republicans and Democrats swiftly denounced the act of violence.

The Trump campaign reported that he was "doing well." The shooting took place less than four months prior to the November 5 election, where Trump is set to face a rematch with Democratic President Joe Biden. Most opinion polls, including those conducted by Reuters/Ipsos, indicate a tight race between the two candidates.

Biden expressed in a statement: "There is no room for this kind of violence in America. We must stand united as a nation to condemn it."

The Secret Service confirmed that the shooter was deceased, with one rally attendee killed and two other spectators injured. The incident is being investigated as an attempted assassination, as reported by a source to Reuters.