(CNN) — A dean at a Boston public high school has been fired after he allegedly shot one of his students in the head.

In addition to his work as “dean of academy” at English High School, Shaun Harrison ran a marijuana distribution enterprise, Suffolk County Assistant District Attorney David Bradley said in a news release.

His victim was a 17-year-old student he had allegedly hired to sell marijuana for him, Bradley said at an arraignment hearing Thursday.

According to police documents, the teen told authorities he was regularly mentored by Harrison, whom he called “Rev.”

Bradley said the two left Harrison’s residence Tuesday evening and were walking along a street when a dispute arose. Harrison then “produced a handgun, pointed it at the back of the victim’s head, and fired,” the release said.

Surveillance footage, which police have not released, captured the incident.

The teen, whom police have yet to identify, was shot behind the right ear, according to a police report. He is expected to survive his injuries, the release said.

Harrison has been charged with armed assault with intent to murder, aggravated assault and battery with a dangerous weapon. He also faces multiple weapons charges.

The 55-year-old had been employed with Boston Public Schools in various roles since 2010.

He had been at English High School since January 5, where as “dean of academy,” he “provided services like finding housing for homeless students or social services or disciplinary alternatives to suspension,” said Denise Snyder, a representative for Boston Public Schools.

His employment has been “terminated effective immediately,” Snyder said.

The Rev. Dr. Gregory Groover is the pastor at Charles Street AME Church, where he said Harrison attended services for 10 years before leaving in 2012. He said the allegations against Harrison aren’t consistent with the man he knows.

“I was stunned beyond description,” Groover said about hearing of Harrison’s arrest.

Groover said Harrison came to his church having already been ordained as a minister at a Baptist church. He recalled Harrison usually attended services alone, but he “got along with everyone.”

“He seemed to consistently care with a deep heart for saving young people who were in the streets or gang related, prison-involved,” Groover said. “That was the population that his life seemed to center around.”

A not guilty plea was automatically entered on Harrison’s behalf. He posted $250,000 bail and is under house arrest, according to police documents. He has been ordered to “stay away and have no contact with the victim” and wear a GPS monitor, the DA’s release said.

He is scheduled to be back in court on April 6.

CNN’s multiple attempts to reach an attorney for Harrison were unsuccessful.