BALTIMORE (AP) - Maryland's highest court has ruled that a Baltimore police officer charged in the death of Freddie Gray must testify against his colleagues while he awaits retrial.

The Court of Appeals issued a ruling Tuesday siding with prosecutors who asked a judge to compel William Porter to testify against the five other officers facing charges stemming from Gray's death. Porter's first trial ended in a hung jury in December.

The rulings affirmed Baltimore Circuit Judge Barry Williams' decision to force Porter to testify against two of the officers and reversed the judge's decision that Porter did not have to testify against the three other officers.

The trial for Lt. Brian Rice was scheduled to begin Wednesday but it has been postponed. The Maryland Court of Appeals ruled Tuesday that Officer William Porter must testify at his colleagues' trials. Porter's own trial ended in a hung jury in December and he is awaiting a retrial.

Terri Charles, a courts spokeswoman, said in an email that Circuit Court Judge Barry Williams will schedule new trial dates for the officers.