Pretrial motions are scheduled to begin for a Baltimore police officer facing criminal charges in the arrest and subsequent death of a young man black whose neck was broken in a police van.

Officer Garrett Miller faces assault, misconduct in office and reckless endangerment charges stemming from Freddie Gray's death in April 2015.

Prosecutors say Miller illegally arrested Gray after the young man ran away from a bike patrol officer and was criminally negligent for failing to buckle Gray into a seatbelt or call a medic when he indicated he wanted to go to a hospital.

Miller testified against his colleagues at previous trials and will be tried by two prosecutors new to the case. Six officers, three white and three black, were charged in Gray's death. So far, trials for four of the officers have led to three acquittals and a mistrial.