To the kids at Boston's English High School, where the Rev. Shaun O. Harrison Sr. was considered the dean of students, the pastor and prominent antigang activist was known by the nickname that adorned his office door: "Rev."
And that, police say, is how a 17-year-old student found bleeding from a bullet fired into the back of his head identified the man who shot him Tuesday.
"Rev," police and prosecutors say, was leading a double life.
Arraigned in Roxbury District Court on Thursday, Harrison, 55, is accused of attempting to execute a student he had been mentoring at English, but was also allegedly selling marijuana as part of the pastor's drug operation.
The reverend who organized gun buybacks and preached nonviolence, officials allege, was also running drugs and hiding gang tattoos below his clerical collar. He is charged with armed assault with intent to murder, aggravated assault and battery, and unlawful possession of a firearm.
Through an attorney, Harrison denied the charges.
In court, Suffolk Assistant District Attorney David Bradley described the alleged attack as an "execution-style shooting" of a teen who survived despite being shot behind the ear.
After arranging a meeting with the unidentified student by text message, Bradley said, Harrison met him at a gas station.
"He had told the victim that they were going to a house to get marijuana and meet up with some girls for the victim," Bradley said.
Surveillance video that prosecutors allege captured the shooting shows a man on a cellphone raise his hand toward the head of a person walking in front of him then fleeing.
Bradley said in court that the student then stumbled into traffic, where he hailed a passing car for help.
The student was taken to Boston Medical Center, where doctors removed a bullet lodged in the boy's cheek. On Wednesday, he told police that he had been selling marijuana for Harrison for the past several months, Bradley said.
The student identified Harrison, and video showed the alleged shooter returning to an apartment on Pompeii Street that belongs to Harrison, he said.
Inside the apartment, the student told police, Harrison had a mural depicting members of the Latin Kings gang, Bradley said.
Harrison, dressed in a gray suit, shook his head in apparent disagreement during the arraignment. Judge David Poole set bail at $250,000 cash.
Three other men were arraigned at the same time on Thursday. Dante Lara, 24, Wilson Peguero, 23, and Oscar Pena, 19, were arrested after police saw them leave the Pompeii Street apartment in an alleged attempt to remove evidence. Their connection to Harrison and the alleged drug operation are under investigation, but two of the men bore tattoos similar to one of Harrison's, said Bradley. All three face drug charges. Lara and Pena are also accused of firearms offenses.
Harrison, who has worked for the Boston public schools since 2010, started working at English High on Jan. 5, school department spokeswoman Denise Snyder said in an e-mail. At English High, Harrison was recognized as dean of students, though his official title was coordinator, Snyder said.
Defense attorney Kernahan Buck said Harrison ran anger management classes and a substance abuse program at English High. He said Harrison has a "strong record of accomplisment in the field of human services" and raised eight children in Boston. "I believe he's not guilty," Buck said after court.
Before joining the staff at English High, Harrison worked as a paraprofessional at the now-closed Odyssey High School in South Boston, a position he held until August 2011 when he moved to Boston Green Academy in South Boston for a job as a "community field coordinator,'' according to a summary of his work history provided by the Boston public schools.
According to Snyder, Harrison's role at English High was as a "community or family outreach coordinator role, charged with coordinating services for students and families."
In a statement released Thursday, interim school Superintendent John McDonough said Harrison was fired Thursday morning.
Harrison was associated with the Charles Street A.M.E. Church, but left in 2012, according to the Rev. Opal Adams, an associate pastor at the Roxbury church.
Adams said she was shocked to hear the allegations against Harrison, who she said she remembered him for his antiviolence work with area youths. "It doesn't sound like our Shaun," Adams said. "It's not the character of the man we knew."
She said she believed Harrison had left for another church nearby, but could not recall its name.
Harrison's sister, Susan, defended her brother in an interview with the Globe.
"My brother is a good man, and I don't know how this happened," said Susan Harrison. "It was a setup."
Shaun Harrison had been involved in several antiviolence and youth outreach programs around Boston over the last decade, and ran — unsuccessfully and largely unnoticed — for City Council in 2009.
Harrison also founded Operation Project Gang Out, an anticrime initiative that encouraged youths to give their illegal guns directly to him, no questions asked.
He worked briefly with Nancy Robinson of Citizens for Safety, who said she was shocked to learn of the allegations against him.
Their paths diverged, she said, when Citizens for Safety focused its crime-prevention efforts on women.
"This is totally unexpected. I've never seen him lose his temper," said Robinson, who called the circumstances of Harrison's arrest "pretty ironic."
"Everything we do, and we work on, is to prevent this kind of incident," Robinson said.
Harrison had also been the overseeing director of Operation Homefront, an antiviolence clergy group, though his involvement was scrubbed from the group's Facebook page. None of the clergy involved with the program returned calls Thursday.
Though police at times turned to Harrison for assistance in building ties to the Roxbury and Dorchester communities, the efficacy of his antiviolence efforts was unclear.
"He wasn't a heavy hitter in our eyes in terms of working for the rehabilitation of young people,'' said a former high-ranking state probation official, who asked not to be identified by name. "We wouldn't summarily dismiss him, but he wasn't someone you would give a lot of credence to in terms of what he was saying.''
The official said that Harrison never provided information about a facility or program that probation officials could assess for its effectiveness. "It was all very nebulous,'' he said.