Marshall Goodwin, chief of the Baltimore City Public Schools' police, resigned on Friday "so that he could pursue other interests," according to television stations WJZ and WMAR.
Schools officials said Wednesday that Chief Marshall Goodwin resigned effective June 10 from the force he has led since 2007.
However, it is clear that he has resigned following the March slapping incident, which forced him into "administrative leave". A district spokesman did not comment.
The incident involved a male officer attacking and kicking a student three times. A female officer just looked on. She had egged the police officer to "smack" the student, as he had been insolent, reports say.
News of the incident just outside Baltimore's REACH! Partnership School had spread like wildfire, which provoked the local media to investigate.
Facing charges of misdemeanour, both the officer who slapped the student and the woman who looked on were charged with assault and misconduct. Goodwin was placed on administrative leave since March.
School officials confirmed that Goodwin was "not involved" in the March incident and "resigned to pursue other interests."
The resignation has been accepted by the school officials, but there are no clarifications as to why he had been placed on paid leave.
Goodwin was appreciated by the district for "developing partnerships with federal, state and local law enforcement agencies." It put out a statement: "City schools is deeply grateful to Goodwin for his service to our schools, students and community, and wishes him well in his future endeavors."
Clyde Boatright, the president of school police union, expressed her sadness at his resignation, and said he will be missed.
"Chief Goodwin has brought a lot of good things to the table during his tenure. We have grown by leaps and bounds under his leadership, but we, as a department, are still committed to the task of securing schools," Boatright said.
Goodwin had been with the Baltimore City's Sheriff's Office for 25 years. He had been a state delegate before he took over the state police.
