Would-be Donald Trump assassin Thomas Matthew Crooks never showed any political leaning in high school and was as “quiet as a churchmouse,” according to his school counselor.

Crooks was “respectful,” never got into trouble and “wasn’t a needy-type kid” during his time at Bethel Park High School, said now-retired counselor Jim Knapp, who never saw any warning signs that could have foreshadowed the shocking attempted assassination Saturday.

“Kids weren’t calling him names, kids weren’t bullying him,” stressed Knapp, who was baffled as to what could have made him “snap.”

Even when students would walk around the halls with political attire supporting Trump or President Biden, Knapp noted that Crooks never joined in.

The retired counselor said he would approach Crooks if he saw him alone in the cafeteria — something he would do to provide help and company to lonely students — and the young man seemed content with being a loner.

Given Crooks’ apathetic disposition and lack of any disciplinary issues, Knapp couldn’t figure out what triggered the former student to attack Trump and his supporters at the Butler rally.

“Anybody could snap, anybody could have issues,” he said. “Something triggered that young man and drove him to drive up to Butler yesterday and do what he did.”

Knapp’s comments echoed what Crooks’ classmates have said, with several describing him as someone with “few friends” but who never stuck out.

One classmate, Jason Kohler, however, claimed that Crooks was “relentlessly” bullied in high school and was known for wearing hunting outfits to class, KDKA reports.

Little remains known of a possible motive for the shooting, in which Crooks, 20, injured Trump and two others and killed a former volunteer fire chief.

Crook was shot and killed after firing at the former president and his supporters at the rally in Butler, with investigators discovering an explosive device in the gunman’s car, which was parked not too far from the campaign event.

With Post wires