Police say there is a serial butt-slapper terrorizing subway trains in Brooklyn. According to authorities, they have received nearly a dozen reports of a man slapping the buttocks of women riding the subway in and around Crown Heights. The incidents date back to June 19.

The victims range in age from 19 to 44 years old, cops say.

Police were reportedly questioning a man Friday, who they believe may be behind the attacks in the area. Whether or not he was the alleged butt slapper has yet to be confirmed.

"He's a lowlife. I think he's a coward and he will be arrested. And he will be sent to jail," said City Councilwoman Letitia James about the suspect police are looking. "It's just a matter of time. We have some good leads. The police are following him."

The suspect is described as being in his mid-20s, between 5-feet-10-inches and 6-feet tall. He is said to weigh between 175 and 200 pounds. He has short black hair and brown eyes.

Anyone with information is asked to contact Crime Stoppers by calling 1-800-577-TIPS, by texting TIP577 to CRIMES, or by going to NYPDCrimeStoppers.com.

Sexual harassment on New York City trains is apparently a rampant, yet unpublicized issue in the Big Apple. A 2007 poll found 63 percent of respondents reporting some form of it in their commutes, and HollaBack NYC chronicles such incidents every week.

Last year the MTA planned an anti-harassment ad campaign in the trains, and briefly backed off it. Many thought officials feared the campaign would give the subway a bad reputation. However, the MTA later reinstated it.

As of Wednesday, the butt slapper was still at large, according to police sources.