The man suspected of terrorizing a Tampa neighborhood for a month and killing four seemingly random people is a former St. John’s University student.

Howell Emmanuel Donaldson III, 24, was arrested Tuesday afternoon and charged with four counts of premeditated murder. He was booked into the Hillsborough County Jail around 3 a.m. Tuesday, New York Daily News reports.

Police say Donaldson was arrested after handing a bag to the manager of a McDonald’s where he worked as a crew leader, before walking across the street to get a payday loan. The manager reportedly found a loaded gun in the bag and alerted a police officer in the store. The officer called for backup and Donaldson was arrested.

Tampa Police Chief Brian Dugan told the newspaper that the manager’s tipoff really helped with the case.

“We got a break. Somebody stepped up and did the right thing.”

Donaldson is accused of killing four people between October 9 and November 14.

READ more: CAPTURED: Police arrest suspected Tampa serial killer and charge him with four counts of murder

He allegedly shot and killed Anthony Taino Naiboa, 20, Monica Caridad Hoffa, 32, and 22-year-old Benjamin Mitchell within 10-days. Ronald Felton, 60, was shot and killed on November 14.

Donaldson reportedly attended St. John’s University where he was a walk-on for the university’s basketball team during 2011 and 2012. A St. John’s University spokesperson confirmed that he never played a game.

His LinkedIn page says he worked as a “guest experience host” for the Mets in 2016.

Donaldson graduated from the university in January after studying sports management.

[Feature photo: Howell Donaldson III/Hillsborough County Sheriff’s Office]