Boston Mayor Marty Walsh is launching an internal review of the employment history of the Boston high school dean accused of shooting a teen in the head over a drug dispute last week.

The Boston Public Schools Department of Labor Relations will carry out the inquiry, which will include interviews with school leaders and other staff members at the schools where Harrison was employed.

Shaun Harrison, a 55-year-old Roxbury reverend, was most recently a dean of students at Jamaica Plain’s Boston English High School. He was fired after the allegations of the shooting came to light last week.

According to Walsh’s office, an initial review of Harrison’s officials records with Boston Public Schools shows no evidence that would have linked him to criminal activity in or out of school.

“The charges against Shaun Harrison are extremely disturbing and I am greatly concerned because of his role with students at English High School," said Walsh in a statement. "It's critical that, in addition to a criminal investigation, we take a thorough look at his employment within our public school system to ensure that we are taking the necessary steps to protect students throughout the city."

Walsh has called a meeting with staff of the Boston Public Schools and the Boston Police Department to discuss the ongoing criminal investigation into Harrison Monday afternoon.

Harrison is alleged to have sold drugs while he was employed at Boston English. A recent search of his home yielded a substantial amount of marijuana, some cocaine and several guns. Police also reported he had a gang mural in his apartment.

A meeting for English High parents will be held this week, although meeting details will be announced by Boston Public Schools once it is confirmed.

"My top concern remains the well-being of the students at English High School," Interim Superintendent John McDonough said in a statement. "I have directed additional staff be assigned to the school to help support students and staff through this difficult time. I spent time at the school on Friday, and I have great confidence in the educators and staff at the school. We have begun a methodical process that will take a comprehensive look at Mr. Harrison's employment history with BPS. When it is concluded, we will share as much of what we learn as is allowed by state law."