The reverend and former high school dean who authorities say shot a 17-year-old male student was arraigned on more charges Tuesday.

Shaun Harrison, 55, of 18 Pompeii St., Roxbury, was held on an additional $150,000 on new charges of unlawful possession of a firearm and single counts of trafficking in cocaine, unlawful possession of ammunition and possession of a firearm in the commission of a felony. His total bail is now $400,000.

Authorities allege Harrison, formerly the dean of students at Boston English High School, shot a teen in the head on Magazine Street earlier this month over a marijuana dispute.

Prosecutors allege Harrison, who has a history of being an anti-gang activist, ran a marijuana ring and used the victim to sell drugs.

A police search of his home yielded drugs and guns.

Harrison is due back in court April 16.