Three former Minneapolis police officers were charged Wednesday with aiding and abetting murder in connection with the death of George Floyd in their custody, Minnesota Attorney General Keith Ellison announced Wednesday.

Derek Chauvin, a fourth former officer who had already been charged with third-degree murder and second-degree manslaughter, will now also be charged with second-degree murder, Ellison said.

"We are here today because George Floyd is not here," Ellison, a Democrat, said at a news conference in St.

Chauvin, who is white, was charged Friday with third-degree murder and second-degree manslaughter after video footage emerged showing him kneeling on Floyd's neck for nearly nine minutes as Floyd, a black man, lay handcuffed, crying out that he could not breathe. .

Drew Evans, superintendent of the Minnesota Bureau of Criminal Apprehension, appeared alongside Ellison and said that one of the officers charged Wednesday was in custody, and the other two were expected to be taken into custody later in the day.

The video shows that Chauvin continued to keep his knee of Floyd's neck even after Floyd became unresponsive. .

Floyd's death has sparked widespread protests against police violence in dozens of cities across the country, with demonstrators and Floyd's family calling for charges to be brought against Thao, Kueng and Lane.

Quincy Mason Floyd, George Floyd's son, said in an interview on CNN after news of the charges broke: "We demand justice.

A second-degree murder charge carries a statutory maximum sentence of 40 years upon conviction, compared with 25 years for third-degree murder.

Thao, 34, Kueng, 26, and Lane, 37, are charged with aiding and abetting second-degree murder and second-degree manslaughter.

But the independent autopsy, conducted by pathologists hired by Floyd's family, found that he died from asphyxiation, and that pressure on both his neck and back contributed

In all, Chauvin held his knee on Floyd's neck for eight minutes and 46 seconds, including for nearly three minutes after Floyd became unresponsive, according to the complaint. 

In an emotional speech earlier on Wednesday, Crump, the Floyd family attorney, said Floyd "cried out for anybody who would listen."

The people who refused to listen were the people who were supposed to listen," Crump said, speaking from the site where Floyd was killed.