The 19-year-old suspect who assaulted and robbed a student at the University of Massachusetts Amherst — and caused the campus to be put on a lockdown — was using a BB gun instead of a real firearm, according to reports.

William McKeown of Framingham was arraigned once again on Wednesday and charged with armed robbery, assault and battery with a dangerous weapon, and assault and battery, reported.

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McKeown had been at first arraigned on Monday and held without bail.

Prosecutors revised the complaint against the 19-year-old stating that it was determined he was using a BB gun during the Feb. 18 incident rather than a firearm, according to the Boston Globe.

Bail was set on Wednesday to $7,500 and if McKeown posts bail, the Globe said, he will be placed on house arrest and be subject to GPS monitoring. He will also no be allowed to have any contact with the victim and witnesses, and cannot use alcohol or drugs

He is expected to return to court on April 11.

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UMass was put on lockdown last week after campus police received a report of a “hostile armed person,” according to The lockdown was lifted once McKeown — who is not a UMass student — was arrested the following day.

McKeown allegedly entered a first-year dorm with a second suspect to sell marijuana to a student but instead a disagreement led to him stealing $120 and assaulting the student, reported.