From Prince William police: 

Brandishing a Firearm – On April 27 at 8:44PM, officers responded to Hylton High School located at 14051 Spriggs Rd in Woodbridge (22193) to investigate a fight with a weapon. The investigation revealed that the victim, an 18-year-old male, and the accused, an acquaintance, were involved in verbal altercation which escalated. During the encounter, the accused brandished a firearm which he had retrieved from his vehicle. The parties eventually separated and the police were contacted. Following the investigation, the accused was located and arrested without incident at his residence later that evening. Further investigation determined that the firearm was a BB gun.