All four of the former police officers involved in the arrest of George Floyd now face charges related to his death, with authorities accusing three men of aiding and abetting his murder.

Former Minneapolis Police Department officers Thomas Lane, J. Alexander Kueng, and Tou Thao were charged on Wednesday, CNN reports.

Derek Chauvin, the man accused of killing Floyd after pressing his knee to his neck, also had his charge upgraded from third-degree to second-degree murder.

Chauvin also stands accused of second-degree manslaughter, and the other three men have been charged aiding and abetting second-degree manslaughter.

All four men were fired after bystander footage of Floyd’s arrest spread online, but until this point, only Chauvin had faced charges tied to Floyd’s death.

“I strongly believe that these developments are in the interest of justice for Mr. Floyd, his family, our community and our state,” said Minnesota Attorney General Keith Ellison.

As pointed out by CNN, aiding and abetting second-degree murder is punishable by up to 40 years behind bars.

“This is a bittersweet moment,” said attorney Benjamin Crump, who represents the Floyd family.

“We are deeply gratified that [Ellison] took decisive action, arresting & charging ALL the officers involved in #GeorgeFloyd’s death & upgrading the charge against Derek Chauvin to felony second-degree murder.”

Two post-mortem investigations found Floyd’s cause of death to be homicide.

Outrage at Floyd’s death has swept across the United States, with protests in every state – and aggressive police crackdowns across the map.

Protests have emerged abroad, as demonstrators worldwide call for an end to racial injustice and state-sanctioned violence.

Image: ABC News / Hennepin County Sheriff's Office