Fairfax County police on Thursday released a new sketch of the man who they believe may be responsible for 18 gropings in the past few months.

Reports in the series of Springfield-area assaults began in September, and the latest attack took place at about 5 p.m. Wednesday. In that incident, a 21-year-old woman was walking in the 6600 block of Grey Fox Drive in Springfield when a man approached her from behind, grabbed her buttocks and fled, police officials said.

Just before Wednesday's attack, the victim was let off a bus near Old Keene Mill Road and Huntsman Boulevard. But there is no indication that the groper was also on the bus, Fairfax County police spokesman Officer Don Gotthardt said.

The sketch is based on a description provided by two women who were groped within 30 minutes of each other in Springfield on Jan. 30. Those women described their attacker as a Hispanic man who is about 5 feet 6 inches tall and had acne or shaving bumps on his cheeks.

Anyone with information can contact Crime Solvers by phone at 866-411-TIPS (8477), by email at fairfaxcrimesolvers.org or by texting "TIP187" plus a message to 274637.