Derek Chauvin was charged with third-degree murder and second-degree manslaughter in the aftermath of kneeling on George Floyd's neck for nearly nine minutes, leading to the African American man's death.
The Minnesota Attorney General who took over the case last week will make the announcement shortly.
A rally and march by the People's Organization Progress is held to protest the death of George Floyd.
According to the charges filed against Chauvin, Lane and Kueng helped Chauvin hold Floyd down while Thoa stood nearby.
Floyd's family was informed by authorities charges were coming, according to the family's attorney Ben Crump. Paul Butler, a former federal prosecutor and author of Chokehold: Policing Black Men talks to Anushka Asthana about why he believes the U.S. justice system needs urgent reforms otherwise the killings of black Americans at the hands of police officers will continue. Minneapolis Police chief Medaria Arradondo fired the four officers and said they were "complicit" in Floyd's death. "We must have equal justice for the United States of America", Crump said. Lane was detailed in earlier charges as pointing a gun at Floyd before handcuffing, and later asked whether officers should roll Floyd on his side as he was restrained.
"He died because he was starving for air", Mr Crump said.
"Our message to them: Find constructive and positive ways to keep the focus and pressure on", they said. Ellison spokesman John Stiles confirmed that Ellison would give an update but would not provide any details. This means that Chauvin was not the only one who caused the victim's death.
Prior to their marriage, Kellie Chauvin at different times used the last names "Thao" and "Xiong".
Lane, 37, and Kueng both joined the department in February 2019 and neither had any complaints on their files.
Kueng was a 2018 graduate of the University of Minnesota where he worked part-time on campus security. He also worked almost three years as a theft-prevention officer at Macy's in downtown Minneapolis while he was in college. He was laid off later that year due to budget cuts and rehired in 2012.
Independent doctors conducting an autopsy for Floyd's family determined the cause of his death was mechanical asphyxia. The University of Minnesota and the Minneapolis Public School district cut ties with the department as a result of the incident.
Chauvin, a Caucasian officer, was seen in the same video with his knee on Floyd's neck before the unarmed black man - who pleaded that he could not breathe - died, sparking more than a week of violent protests.