BOSTON (CBS) – Police have identified the man wanted for spitting on an MBTA bus driver last month.

Officers have issued an arrest warrant for 21-year-old Raphael Guzman, who is facing assault charges.

Guzman and Maurice Jones, who was arrested last week, boarded the MBTA bus in Roxbury on April 18 and got into a dispute with the driver over the bus fare.

Guzman spat on the driver before running out of the bus.

Jones, meanwhile, is accused of threatening the driver by gesturing that he had a gun concealed in his waistband before he left the bus. He was charged with assault by means of a dangerous weapon.

Anyone with information regarding Guzman’s whereabouts is asked to contact Transit police.