Shaun O. Harrison, the former English High School dean known in Boston as an antiviolence activist, was convicted Thursday of shooting a 17-year-old student he had enlisted to sell marijuana for him.
The jury found Harrison, 58, guilty of all 10 counts brought against him a day after deliberations commenced in Suffolk Superior Court. He is scheduled to be sentenced Friday morning before Superior Court Judge Christopher Muse.
After the verdicts were read, Suffolk District Attorney Daniel F. Conley said Harrison had presented himself as a “man of God” and a youth mentor, but instead preyed upon the victim, Luis Rodriguez, who was a high school sophomore when he was shot in Roxbury on March 3, 2015.
“What we were able to uncover here is that Shaun Harrison was really a fraud,” Conley said. “He was living a lie.”
During the two-week trial, prosecutors portrayed Harrison, who went by the nickname “Rev,” short for reverend, as a sinister manipulator who used his authority to recruit Rodriguez to sell marijuana for him.
Prosecutors alleged Harrison shot Rodriguez because he feared officials would learn the student was selling marijuana at the Jamaica Plain school. Harrison also believed Rodriguez, now 20, was withholding money and not generating enough sales, prosecutors said.
“He didn’t want to give up the sort of privileged lifestyle that he had become accustomed to and he was willing to kill to preserve that,” Conley said.
Harrison looked straight ahead as the verdicts were read, while his daughter, Lishaunda, stormed out of the courtroom. He faces up to 20 years in prison on the most serious charge, armed assault with intent to murder. The jury also convicted him of aggravated assault and battery by means of a dangerous weapon, and several offenses related to illegal possession of firearms, ammunition, and marijuana.
Boston Police Commissioner William B. Evans praised the investigators, prosecutors, and jury.
“It’s especially disappointing that a person who was trusted by the community to be a mentor to our youth betrayed that trust in such a drastic way, so I hope this decision brings some peace of mind to all those who may have been affected by Harrison’s actions,” Evans said in a statement.
Rodriguez, who was not in the courtroom when the verdicts were read, testified for the prosecution, telling jurors he met Harrison in early 2015.
Harrison was hired at English High to be the dean of academies and was responsible for keeping order in hallways and the cafeteria, mentoring troubled students, and teaching anger management, according to court testimony.
A Boston Public Schools spokesman declined to comment Thursday.
Harrison’s sister, Kathleen, said she didn’t believe the prosecution’s witnesses and complained that her brother’s good works weren’t mentioned.
“They messed up my . . . brother’s reputation,” she said. “They all lie.”
Rodriguez, the shooting victim, told jurors he came from a dysfunctional family. His mother went to jail when he was 4 years old, he said, and he went to school while high on marijuana.
The teenager said he bonded with Harrison during an encounter in the school cafeteria. Rodriguez said he was high on marijuana during that meeting, and Harrison laughed and told him he had smoked marijuana the night before.
On another occasion, he said, Harrison offered to provide him with marijuana to sell, on the condition that Rodriguez would give him the proceeds. Rodriguez said he agreed and detailed three occasions when Harrison gave him marijuana to sell.
Up until the shooting, Rodriguez said he believed he was on good terms with Harrison, who hosted him at his Roxbury apartment, where they smoked marijuana and the dean let him handle a firearm.
On the day of the shooting, prosecutors said Rodriguez’s longtime friend attacked him at school at Harrison’s direction.
Later that day, Rodriguez said, he met Harrison at a Sunoco station in Roxbury. Harrison had told him he would bring him marijuana and some of the drug molly, Rodriguez said, and then take him to a spot to meet women.
When they reached Magazine Street, prosecutors allege Harrison fired a .380 handgun at Rodriguez and then fled. Rodriguez said he was rescued by occupants of an oncoming car, who called 911.
The bullet entered Rodriguez’s head just under his right ear, narrowly missing his carotid artery, breaking his jawbone, and causing nerve damage and hearing loss.
Defense attorney Bruce Carroll acknowledged Harrison was guilty of some of the firearms and ammunition offenses. When police searched Harrison’s home after Rodriguez was shot, they found a shotgun and rifle that Harrison had inherited from his parents but didn’t have a license to carry, Carroll said.
But he disputed allegations that Harrison shot Rodriguez, telling the jury that the teenager told hospital staff that he had been shot by a person who bought marijuana from him. He repeatedly said Rodriguez was conscious and talking in the immediate aftermath of the shooting but didn’t disclose he had been shot by Harrison.
Suffolk Assistant District Attorney David Bradley said Rodriguez’s chief concern after being shot was his survival. He said he repeatedly asked the same question as blood poured from his head: Am I going to die?Travis Andersen of the Globe staff contributed to this report. Laura Crimaldi can be reached at email@example.com.