Officer William Porter, one of six Baltimore city police officers charged in the death of Freddie Gray, arrives to Maryland Court of Appeals, Thursday, March 3, 2016, in Annapolis, Md. Maryland's highest court will hear arguments Thursday on whether Porter can be compelled to testify against his colleagues after his trial ended in a hung jury in November. (AP Photo/Jose Luis Magana)

Officer William Porter, right, one of six Baltimore city police officers charged in the death of Freddie Gray. Porter is one of two officers who prosecutors want to testify against their colleagues. (AP Photo/Jose Luis Magana)

Prosecutors in Baltimore want to compel a second police officer charged in the Freddie Gray case to testify against a fellow officer.

Media outlets report that a motion seeks to compel Officer Garrett Miller to testify at Officer Edward Nero’s trial. Both were involved in Gray’s arrest and have pleaded not guilty to second-degree assault, reckless endangerment and misconduct. Gray died in April 2015 after he was injured in police custody.

The motion filed last week comes after a decision by the state’s highest court that Officer William Porter can be compelled to testify. The Court of Appeals issued the order March 8, but hasn’t delivered an opinion explaining its reasoning.

If the motion is granted, both Porter and Miller could be witnesses at Nero’s trial.