NEW YORK (CBSNewYork) — He was supposed to be teaching them karate, but students say more than that was going on.

Now, a Manhattan karate teacher stands accused of sexually abusing underage female students, CBS2’s Dave Carlin reported Sunday.

Hector Bencosme was seen coming out of a precinct station house with his head held up, until he caught sight of members of the media. It was head down for the rest of the 57-year-old karate instructor’s slow walk in handcuffs to the police car that took him to court.

karate Manhattan Karate Teacher Busted On Underage Sex Charges

Hector Bencosme, center, is escorted to court by NYPD investigators. (Photo: CBS2)

He was arraigned on charges, including aggravated sexual abuse and child pornography.

Prosecutors say he sexually assaulted four girls over the past two months during karate lessons held in a building on Post Avenue in Inwood.

“I saw the sign there about karate lessons over there,” resident Javis Aristy said.

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Aristy noticed that the sign recently disappeared. It was replaced by neighborhood fear for some now that a man trusted with kids has been accused of sexually touching minors and taking explicit photos of them.

“Know who you’re leaving them with. That’s scary. I have a daughter,” Aristy said. “Got to be careful who you trust — background checks and everything.”

“Unbelievable. That’s crazy. You can’t trust anybody in this world,” resident John Disla added.

Bencosme lives in an apartment building in Washington Heights. One woman identified herself to CBS2’s Carlin as Bencosme’s wife. She was joined by a next-door neighbor and they both said they believe Bencosme treats young students with respect.

The neighbor said she believes the accusations are false and the girlfriend said while she cannot know for certain what happened during those basement lessons, she knows Bencosme to be a good man.

CBS2 has learned Bencosme was charged with second-degree sexual abuse and endangering the welfare of a child back in 2000. At some point he left the United States. It wasn’t immediately clear if he was convicted in the earlier case.

The accused instructor is due back in court on June 1.