Metropolitan Police Officer Michael Fanone, who suffered a heart attack and traumatic brain injury after being violently assaulted Jan. 6, received a threatening, expletive-laced voicemail on his cellphone as he testified Tuesday about his experience during the Capitol riot.

“I could slap you up the side of your head with a backhand and knock you out, you little f-----,” the caller said in his message, which Fanone shared on CNN.

"I wish they would have killed all you scumbags, 'cause you people are scum," the man, who used homophobic and racist slurs in his message, continued after repeating former President Donald Trump’s false claim that the presidential election was stolen.

“They stole the election from Trump and you know that, you scumbag. And f---ing too bad they didn't beat the s--- out of you more,” the caller said.

CNN aired the voicemail uncensored several times since Fanone received it.

“Unfortunately, I’ve come to expect this type of response,” he told CNN’s Don Lemon about the message. “It’s not the first time that people have expressed similar opinions to me. ... There is an element in this country that believes that.”

Fanone was among four officers who testified Tuesday at the first hearing of the House select committee investigating Jan. 6. He told the lawmakers on the panel that he was at risk of getting killed with his own firearm by the mob participating in the riot.

"I was grabbed, beaten, tased, all while being called a traitor to my country," he said in his opening statement.

Rioters dragged him into the crowd, grabbed his badge and ammunition and beat him with the metal objects and their fists, he said.

“I was electrocuted again and again and again with a taser," he said.

During the hearing, Fanone and other officers asked lawmakers to look into the events leading up to the riot and whether those in power played any role in provoking the attack.

"It's interesting from a law enforcement perspective, as a police officer — a lot of these events happened in plain sight. We had violent political rhetoric," he said.

[nbcnews.com]