By Elizabeth Barber

BOSTON (Reuters) - A Massachusetts high school dean charged with the attempted execution-style murder of a student he had inducted into an alleged drug ring had once worked with Boston police on efforts to combat drugs and gangs, a police spokesman said on Friday.

Prosecutors contend that Reverend Shaun Harrison, the now-fired dean of The English High School, hired one of his students to sell marijuana and shot the 17-year-old boy in the back of the head on a Boston street Tuesday night after a disagreement.

The victim, whose name was not released due to his youth, is expected to survive his injuries, according to the Suffolk County District Attorney’s Office. Prosecutors say the incident was recorded on a surveillance camera at a nearby business. 

Harrison was an advocate for struggling teenagers who had worked with police on a number of outreach efforts, including serving as a member of the Boston TenPoint Coalition, a group of Christian clergy members working with black and Latino youth, said Boston police spokesman Lieutenant Mike McCarthy.

Harrison was fired from his job at the English High School on Thursday. Since joining the faculty as dean of academy in January, he had worked on providing social services to students, including finding housing for homeless teenagers or seeking disciplinary alternatives to suspension, said Boston Public Schools spokeswoman Denise Snyder. He had previously held community organizing-related positions at three other Boston schools.

Harrison was arrested on Wednesday night at his home and was arraigned on Thursday on charges of armed assault with intent to murder and aggravated assault and battery with a dangerous weapon, as well as five firearms-related charges. He was released to home confinement on $250,000 bail.

Three other men, all in their teens or early 20s, also were arrested at Harrison's home this week on charges including possession of marijuana and firearms. Two of them bore tattoos similar to those Harrison has, and investigators are looking into their connections to an alleged drug ring, prosecutors say. 

Harrison's attorney did not immediately return a request for comment.

(Editing by Scott Malone and Bill Trott)