It has been two years since the murder of a Black man by a white police officer sparked protests across the US and around the world. Americans are revisiting the debate over addressing police brutality and racism, following George Floyd's death.

President Joe Biden has signed an executive order to reform policing and ensure "fair and impartial justice."

Biden said, "It's a measure of what we can do together to heal the very soul of this nation, to address profound fear and trauma, exhaustion, particularly Black Americans have experienced for generations."

The president invited Floyd's family to the signing ceremony, and the families of other victims of police killings.

Floyd died after former officer Derek Chauvin knelt on his neck for more than 9 minutes.

The murder revived the Black Lives Matter movement and amplified calls for police reform. The president's order directs all federal agencies to ban chokeholds and neck restraints unless deadly force is authorized.

The measure limits when officers can enter a property without knocking, including when that would pose an imminent threat of violence.

All federal agencies must participate in creating a database to help track records of misconduct. But the president can't require local police forces to follow his order. Still, he's encouraging them to make similar changes.