An off-duty Washoe County Sheriff’s Office deputy witnessed a road rage incident on Greg Street in Sparks Wednesday afternoon, and made an arrest. 29-year-old Robert Mosher was booked on suspicion of assault with a deadly weapon, misdemeanor battery, and resisting. The incident happened about 2:45 p.m. near South Rock Boulevard and involved three drivers. Police say the deputy witnessed Mosher force a confrontation and pull out a knife. The deputy then approached, identified himself and held the group at gunpoint. Mosher fled in his vehicle, he was found about two hours later and arrested.