Detroit police officer and union President Mark Diaz was suspended without pay after being charged with two crimes for crashing into a Holly Academy charter school Dec. 20.

He was not on duty.

More than two months after the incident, Diaz was arraigned Friday on on counts of felony malicious destruction of property and misdemeanor reckless driving.

Authorities haven't revealed what they believe led to the crash or why it took months for charges to be filed.

Representatives at Holly Academy declined to comment and Diaz did not answer when called Monday.

Diaz, who was arraigned in Clarkston's 52-2 District Court, is free on a personal recognizance bond. He's been ordered not to return to the school and is scheduled for a probable cause hearing March 3 and a preliminary examination March 10.

"Certainly we're concerned and surprised," Detroit Police Chief James Craig said after the charging announcement. " ... As I've done consistently throughout my tenure here, whenever an officer is charged with a felony, at the time of charging he is suspended without pay."

Craig said Diaz personally notified him after learning of the charges and has cooperated with state police during their investigation.