Prosecutors are charging a Minneapolis police officer accused of pressing his knee against George Floyd’s neck with second-degree murder, and for the first time are leveling charges against three other officers.

Bystander video showing Floyd’s May 25 death has sparked violent protests nationwide and around the world.

The officer, Derek Chauvin, was fired May 26 and initially charged with third-degree murder and second-degree manslaughter.

Three other officers were also fired but weren’t immediately charged.

The Star-Tribune reports that Attorney General Keith Ellison will charge Thomas Lane J. Kueng and Tou Thao with aiding and abetting murder.

The Floyd family on Wednesday visited a makeshift shrine at the Minneapolis street corner where Floyd died on May 25 after a white officer pressed a knee on the black man's neck as he pleaded for air.

A full autopsy of Floyd has been released and provides several clinical details, including that Floyd had previously tested positive for COVID-19. The 20-page report released by the Hennepin County Medical Examiner’s Office came after the coroner’s office released summary findings Monday that Floyd had a heart attack while being restrained by officers, and classified his May 25 death as a homicide. The report also said Floyd’s lungs appeared healthy but he had some narrowing of arteries in the heart.

Senate Majority Leader Nicole Cannizzaro issued the following statement on behalf of the Nevada Senate Democrats:

“We share our fellow Nevadans' horror and sense of shame as we are again confronting the legacy of systemic racism in law enforcement and police brutality directed at Black Americans. What happened to George Floyd, and so many before him, was a despicable act of murder. We have the highest respect for those who are peacefully exercising their constitutional right to protest as an expression of their justified outrage. Violence, however, on any side, is not the answer. We were horrified to hear that a Las Vegas Metro Police Officer was shot on Monday night, and we are praying for his recovery.

From criminal justice to education to health care, racial inequality exists everywhere in our country, and, unfortunately, Nevada is no exception. We firmly believe that racism must be dismantled with the same vigor it was so pervasively established. We must tackle it at all levels, and build a system that upholds equality and fair treatment for all. Nevada Senate Democrats are committed to fighting to make our system a more just one. While the next legislative session will not convene until February, we can begin the work now to identify community needs and shape legislation to address them. We must begin that process now because for George Floyd and so many others, it is tragically already far too late.”

(The Associated Press contributed to this report.)