A warning that police reform in the US will take a very long time

Former police officer Derek Chauvin is due to be sentenced in mid-June after being found guilty on all charges relating to the death of George Floyd.

The US Justice Department has since announced a civil rights investigation into the Minneapolis Police Department.

Washington Post correspondent Kim Bellware says there was a similar inquiry in Chicago after the shooting of Laquan McDonald in 2014.

She says bringing a charge against police is just the first hurdle.

Bellware says a lawsuit is supposed to guarantee changes in the department, but this has had limited success in the past.