Experts say it will be a challenge for prosecutors to convict an Albuquerque police officer and a retired detective of murder after they were ordered to stand trial in the fatal shooting of a homeless man.

Michael Benza of Case Western Reserve University School of Law says officers are rarely sent to prison for on-duty shootings because the law gives them protection based on their perceptions during dangerous encounters.

Benza says that if defense lawyers convince jurors that the officers felt afraid, it will be difficult to get convictions.

A judge ruled Tuesday that Officer Dominique Perez and former Detective Keith Sandy should stand trial. They face charges of second-degree murder and voluntary manslaughter in the 2014 death of James Boyd, whose shooting was caught on video and sparked national outrage.