Police earlier said the alleged shooter was a guest at the hotel where the White House Correspondents' Dinner was being held
"Was it a grievance, a political motive?" he questions, adding that this is what officials will be looking into at the moment. As a reminder, police said earlier that the motive remains unclear.
On the security response, Kroeger says: "This is exactly what the Secret Service is trained do to."
When the threat occurred, they "converged on the president", creating a "body barrier", he says. The president was then removed from the venue to a safe location, he adds.
We've just seen a statement from the US Secret Service, who brought down the suspect who opened fire at a dinner attended by President Donald Trump last night.
"Tonight, a coward attempted to create a national tragedy. He underestimated the protective capabilities of the US Secret Service, and was stopped at first contact," a statement from Deputy Director Matthew Quinn reads.
The "strength of our layered security posture was evident," says Quinn, who notes there was "a myriad of countermeasures still ahead".
He adds: "Grateful for the brave men and women of the Secret Service and our valued Law Enforcement partners."
The alleged gunman who fired shots at the White House Correspondents' Dinner a few hours ago has been named as Cole Tomas Allen, according to US media.
The 31-year-old is reportedly from Torrance, California - in the south-western suburbs of Los Angeles.
CBS News, the BBC's US partner, says Allen worked as a tutor in Torrance after graduating from the highly regarded California Institute of Technology.
Police say he was a guest at the Washington Hilton hotel, where the dinner was taking place, and was carrying multiple weapons - including guns and knives.
Allen is receiving hospital treatment following the incident. He is expected to be formally charged on Monday.
At about 20:35 ET (00:35 GMT, 01:35 BST): Shots are heard at the Washington Hilton and guests take cover. Shortly after, Secret Service agents rush to Donald Trump and escort him and his cabinet out of the room.
21:17: Donald Trump makes his first comments, writing on Truth Social that the alleged gunman "has been apprehended".
21:36: Trump says he is leaving the Washington Hilton at the request of law enforcement.
22:29: The US president shares footage that appears to show the start of the shooting, and follows it up shortly after with a photograph of the suspect.
22:30: Trump holds a news conference from the White House, alongside FBI chief Kash Patel and Acting US Attorney General Todd Blanche. Trump says the "impression" is that the suspect was a "lone wolf".
About 22:50: US media, including the BBC's US partner CBS, name the suspect as 31-year-old Cole Tomas Allen, citing multiple sources.
About 23:10: Live pictures start coming in, showing a police search of a property in Torrance, California.
About 23:15: US Attorney for the District of Columbia, Jeanine Pirro, says authorities plan to formally charge the suspect in federal court on Monday.
The BBC's US partner, CBS News, reports that the alleged gunman has told authorities he was targeting officials linked to US President Donald Trump.
Citing two unnamed sources, CBS also says that at least five to eight gunshots were fired during the incident.
