Trump shooting updates: Shooter flew drone near site hours before shooting

Thomas Matthew Crooks, the 20-year-old suspected gunman, planned to attend Robert Morris University this fall, according to a school spokesperson.

Robert Morris University is a private, four-year university located outside of Pittsburgh.

"We have been in touch with law enforcement and stand ready to assist in their investigation," school spokesperson Brian Edwards said.

Crooks had earned his associate degree in science from a local community college and graduated in May with high honors.

He was accepted into both RMU and the University of Pittsburgh, a public-research university also a close drive from his home in Bethel Park, Pennsylvania.

A spokesperson for the University of Pittsburgh said Crooks was told in February that he could attend this fall semester as a transfer student. In March, Crooks informed Pitt that he would not attend.

-ABC News’ Anne Flaherty

The suspected gunman who attempted to assassinate former President Donald Trump at his campaign rally Saturday purchased 50 rounds of ammunition ahead of the event, according to a bulletin from the Department of Homeland Security and the FBI Monday.

Thomas Matthew Crooks purchased the rounds from a gun and ammunition shop in Bethel Park, Pennsylvania, according to officials.

The bulletin notes that two improvised explosive devices were found in the shooter's car and one at his home.

"Over the last several months, Crooks received several packages, including some marked as possibly containing hazardous material, according to a review of his shipping history," officials wrote.

Officials also warn of future "follow-on or retaliatory acts of violence in response to this assassination attempt."

"We cannot rule out the possibility that some DVEs (Domestic violent extremists) or other actors may attempt follow-on or retaliatory acts of violence in response to this assassination attempt."

-ABC News' Mike Levine

Thomas Matthew Crooks, the suspected gunman in the deadly campaign rally shooting Saturday, did not have any disciplinary problems while attending community college and graduated with "high honors," the school said in a statement Monday.

Crooks, 20, graduated from Community College of Allegheny County (CCAC) in May of this year and majored in Engineering Science, according to the college.

"This individual graduated from CCAC with high honors on May 16, 2024, and was conferred an Associate in Science degree," spokesperson Dena Rose Buzila said in a statement. "In addition, based upon our preliminary review, CCAC has no records relating to any disciplinary, student conduct or security-related incidents involving the identified individual."