A Baltimore police officer was cleared Monday of all charges in the case of Freddie Gray, an African American who died in custody last year, sparking riots and fuelling a nationwide debate about US police brutality.

The verdict handed down by a Baltimore judge found Edward Nero not guilty of second-degree assault, of reckless endangerment or of misconduct in office.

Nero is one of six officers being tried over the death of the 25-year-old Gray, who was picked up on April 19, 2015 and suffered a snapped spine while being transported unrestrained in the back of a Baltimore police van.