Complaints by female subway riders in New York are rising and the NYPD has been conducting undercover investigations with female officers to snare gropers.
Complaints have risen 4 percent in 2009, even while arrests have fallen 6 percent, according to an announcement that was reported by several media outlets.
Underground trains running from Grand Central to Union Square were identified as the most problematic for inappropriate touching.
Police advised female riders to use cellphones to photograph suspects.