Two still in critical condition; campaigns on high alert

The nation is shaken and elected officials and law enforcement are on high alert from Washington to California for any additional threats.

The FBI has identified the shooter, now deceased, as 20-year-old Thomas Matthew Crooks of Bethel Park, Pa., a registered Republican. He used a semi-automatic weapon, NBC News reports.

“We’re all Americans, and we have to treat one another with dignity and respect,” House Speaker Mike Johnson (R-La.) said in an interview Sunday on NBC News’ “Weekend Today.”

Just a day before the Republican National Convention begins in Milwaukee, several Republicans and Trump allies blamed Democratic rhetoric that they said demonized Trump, for inciting the violence.

CNBC’s politics reporters and breaking news teams are covering the day’s developments from Washington, D.C. and New York City.