LANHAM, Md. (CBSDC)- A 21-year-old woman who was grabbed by a stranger while walking in Springfield Wednesday may be the serial groper’s 18th victim.

The victim was alone on the 6600 block of Grey Fox Drive when a man approached her from behind, grabbed her buttocks and ran away.

She described the man as white or Hispanic, between 5-foot-6 and 5-foot-8, and approximately 180 pounds. He was wearing a gray T-shirt with blue sleeves, dark sweatpants and white sneakers.

Police are investigating the possibility that the Wednesday assault is related to 17 similar incidents that have occurred in the area over the past several months. Many of the victims, who range in age from 15 to 49, have described their attacker as a Hispanic male.

Detectives have released a new composite sketch of the suspect based on two incidents of assault reported within 30 minutes of each other on Jan. 30. In both of those cases, the suspect was described as having acne or shaving bumps on his cheeks.

Locations where police believe the serial groper has struck so far in 2013. The red marker is where the Feb. 6 assault took place:

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