Trump gunman Thomas Crooks used bike to scout rally

Would-be Trump assassin Thomas Matthew Crooks rode his bicycle around the former president’s rally in Butler, Pennsylvania — and ditched it in full view of cops and a crowd before he climbed on top of a roof and opened fire, law enforcement sources and witnesses confirmed to The Post.

Exclusive photos showed the gunman’s bike parked beneath a tree just yards away from the building where he fired up to eight shots, grazing Trump’s ear and killing a hero firefighter and wounding two other supporters.

A witness first noticed the bike at 5:30 p.m. — when Crooks was busy scoping out the perfect spot and more than 40 minutes before he fired gunshots.

It’s the latest damning piece of evidence that Crooks, who was deemed suspicious up to three hours before the shooting, was able to move freely around the supposedly secure area.

Law enforcement sources said that Crooks was identified as “suspicious” an hour before the shooting, and the Secret Service deemed him a “threat” 10 minutes prior to Trump going on stage, but let the GOP nominee take the podium anyway.

ABC News reported that he was spotted on the roof by Secret Service counter-sniper teams 20 minutes before he opened fire.

“I noticed it at 7 p.m. [nearly an hour after the shooting]. Still in the same area, still in the same position,” a witness, who asked to remain anonymous, said of the bike — which was left with a host of gear.

“I just found it an oddity,” the witness said after seeing the bike in the same spot nearly an hour after the shooting.

“Whose bike is it? Whose bike? Why would you leave a scene? Why would you leave a bike there?

The images show several police officers running toward the action and away from the lone bike, which had what appears to be a shirt flung over the handlebars, shoes ditched at the pedals and a backpack propped against the wheels.

By that time, Crooks was dead. Secret Service agents returned fire seconds after the 20-year-old took aim at Trump.

Law enforcement sources confirm that investigators believe Crooks used a bike to scope out the vast grounds in and around the Butler County Farm Show.

It’s unclear whether Crooks rode his bike while carrying the AR-style assault rifle, which would have been obviously visible to anyone who saw him.

The killer was on law enforcement’s radar well before he made the assassination attempt — one local cop snapped two pictures of the “suspicious person” looking for the perfect spot to open fire.

Crooks first raised the alarm at 3 p.m. when he passed through the security screening area with a rangefinder, a device similar to binoculars used by hunters and target shooters to measure distances for long-range shots.

An officer spotted Crooks using the rangefinder and looking at his phone nearly an hour before Trump took the stage.

Crooks waited until Trump took the stage to climb on the roof — during which time several witnesses noticed the gunman — before taking the first shot at 6:11 p.m.

Officials later recovered an AR-style rifle, which they believe Crooks stole from his father.

Authorities have not yet shared a possible motive for the shooting.