Local officials and law enforcement will testify on Thursday before the congressional task force investigating the two assassination attempts against former president and GOP nominee Donald Trump. 

This is the first hearing conducted by the task force and will focus on the Butler, PA assassination attempt where shooter Thomas Crooks fired on Trump's rally, killing one and injuring three, including the former president who was struck in the ear. 

"It's the obligation of this of this Congress, this administration, and public servants at all levels of government to stand against those who would use violence to interfere with our elections," said task force Chairman Mike Kelly, R-Penn., said in his opening statement. 

"Every American should be outraged, regardless of who they intend to support by these attempts to nullify their votes through violence. We use ballots, not bullets, to make a determination who's to serve. Today's hearing is the task force's, latest attempt to seek accountability and answers on what happened in Butler, Pennsylvania and to restore the faith, trust and confidence the American people deserve," he continued. 

Witnesses include: Sergeant Edward Lenz of the Adams Township Police Department, the Commander of the Butler County Emergency Services Unit ;  Patrolman Drew Blasko of the Butler Police Department; Lieutenant John Herold of the Pennsylvania State Police; Allegheny County Medical Examiner Dr. Ariel Goldschmidt; and Former United States Secret Service Agent  Patrick Sullivan. 

The hearing follows an initial investigation by the task force which visited the rally site, collected documents, and conducted 23 transcribed interviews with witnesses.