Presumptive Democratic presidential nominee Joe Biden on Wednesday condemned the death of an African American man after he was taken into police custody in Minnesota, referring to the incident as a “horrific killing” that required a civil rights investigation by federal authorities.

“Watching his life be taken in the same manner, echoing nearly the same words of Eric Garner more than five years ago — ‘I can’t breathe’ — is a tragic reminder that this was not an isolated incident but a part of an ingrained systemic cycle of injustice that still exists in this country,” Biden said.

Viral video emerged this week showing a Minneapolis police officer kneeling on the neck of George Floyd, an unarmed man who cried that he could not breathe and later died. Garner, who also was African American, died in New York after a struggle with police in 2014.

Biden, who made his comments at the start of a virtual discussion about the coronavirus pandemic with Pennsylvania Gov. Tom Wolf (D), has come under scrutiny in recent days after suggesting in a radio interview that African Americans who are considering voting for President Trump “ain’t black.” He quickly expressed regret for that remark.

Floyd’s death has prompted widespread outrage. It comes amid a national outcry over the shooting of Ahmaud Arbery, a young black jogger in Georgia who died in a struggle with white men who had followed him with guns.

Four Minneapolis police officers were fired Tuesday and the police chief there said he asked the FBI to investigate the matter. Biden commended Minneapolis Mayor Jacob Frey (D) and the police department for taking “swift action to fire the officers involved.” But he said more needs to be done.

“I don’t think that’s enough. They have to be held more fully accountable,” Biden said. He said this should happen through the FBI probe and called for “an independent Department of Justice civil rights investigation.”

“We have to get to the root of all this,” Biden said.