 As for motive, police have finished searching his home and car and come up with nothing. Noting he also did not appear to have a social media footprint. Liam Campbell, a neighbor of Crooks, says the gunman almost exclusively stayed to himself. He sat by himself, didn't talk to anyone, like didn't even try to make conversation. So it was just kind of odd. He was an odd kid. NBC News reports local police notified the Secret Service they were looking for a suspicious person in the area shortly before the shooting.