In the hours and days following the attempted assassination of former President Donald Trump during a campaign rally on Saturday, law enforcement officials and the public are looking for information about the shooter who killed one attendee and wounded three, including the Republican presidential candidate himself .

The FBI has identified the shooter as 20-year-old Thomas Matthew Crooks , a resident of suburban Pittsburgh who was killed by law enforcement on Saturday soon after opening fire from a rooftop near the rally. As of Sunday, law enforcement officials still have not shared a possible motive for the shooting.

Heres what investigators have revealed so far in their probe of Crooks and the shooting which they said they are treating as a case of attempted assassination and possible domestic terrorism.

He worked at a nursing home, where his background check was clean.

After Crooks graduated from Bethel Park High School in 2022, he began working as a dietary aide at Bethel Park Skilled Nursing and Rehabilitation Center.

The facility learned on Sunday morning that Crooks was behind the shooting at Trumps rally, according to a statement by administrator Marcie Grimm that was obtained by CNN .

The home is cooperating with authorities and can only give limited information due to the ongoing investigation.

We are shocked and saddened to learn of his involvement as Thomas Matthew Crooks performed his job without concern and his background check was clean, Grimm said in the statement. Our thoughts and prayers go out to Former President Trump and the victims impacted by this terrible tragedy.

Records showed that Crooks had no criminal cases against him.