NEWPORT — The Vermont man charged with driving a tractor over seven police vehicles and crushing them has been found incompetent to stand trial.

Roger Pion of Newport had already been involuntarily committed to the custody of the state commissioner of mental health.

He’s been at Fletcher Allen Health Care.

The 34-year-old Pion had faced multiple criminal counts after police say he drove his dad’s tractor over six cruisers and a van at the county sheriff’s department in Derby in August, causing about $300,000 in damage.

Police said he was angry over a previous arrest for marijuana possession. Pion pleaded not guilty.

The Caledonian-Record reports (http://bit.ly/ULiq8d) a judge agreed to a hearing to determine how and where Pion will receive treatment. Prosecutors asked for another evaluation in 90 days.