The gunman who attempted to assassinate former President Donald Trump on Saturday was identified as 20-year-old Thomas Matthew Crooks, sources told The Post.

Crooks, of Bethel Park, Pa., squeezed off at least five to seven shots — one of which grazed Trump in the ear — at an outdoor rally in Butler, just outside Pittsburgh, according to law enforcement sources.

Sources said Crooks crawled onto the roof of a manufacturing plant more than 130 yards away from the stage at the Butler Farm Show grounds.

He was killed by Secret Service snipers.

Authorities recovered an AR-style semi-automatic assault rifle from the scene. He was also wearing a shirt for a popular gun YouTube channel called Demolition Ranch.

Bethel Park is a village 40 miles south of where the Butler rally was held.

According to state voter status records, Crooks was a registered Republican.

The shooter made one $15 donation to the liberal ActBlue political action committee on January 20, 2021 — Biden’s inauguration day, the Intercept reported.

At the time of the donation, Crooks was 17 years old. He registered to vote upon turning 18 in September that same year as a member of the GOP, records show.

Here’s the latest on the assassination attempt against Donald Trump:

Crooks was a member of the 2022 graduating class at Bethel Park High School, the school district confirmed Sunday morning.

Video shows him walking across a stage to accept his diploma.

He also received a $500 National Math and Science Initative Star Award during his graduating year, TribLive reported.

Why Crooks fired on the presumptive Republican presidential nominee is unclear.

Early Sunday, the FBI officially confirmed The Post’s reporting, calling Crooks the “subject involved” in the attack on Trump.