What to Know The woman seen on surveillance video chasing after and hitting a man who allegedly groped her at Grand Central is speaking out

Chantal Castanon says the man's calm demeanor after sexually assaulting a stranger is what terrified her

She's speaking out in the hopes of getting him off the streets

The woman seen on surveillance video chasing the man who grabbed her buttocks in the subway is speaking out about her alleged attack, describing her instinct to go after him and helping to make sure it doesn't happen to anyone else.

Chantal Castanon, 26, was heading home to Staten Island through Grand Central on Aug. 31, in a good mood after getting off work early -- until she felt the stranger's hand on her behind.

"He did it with such a firm grip that I still felt him -- and he was all the way over there already," she told News 4 New York Friday.

Castanon's angry reaction was caught on camera: "I just put the phone in the bag, I didn't even think about it. I just went after him, I just kept hitting him."

News 4 NY

Subway surveillance video showed her hitting the alleged groper over and over, even chasing the man down a corridor.

"I still was willing to take whatever punches or whatever he was willing to throw back at me," she said.

Unafraid of getting hurt, Castanon said she was terrified by the man's "relaxed" demeanor after sexually assaulting her, a stranger.

"Like this was normal for him," she said. "And that scared me the most."

Castanon said fellow subway riders came to her aid. Some tried to help her catch the man and even went to the police station with her to file a report.

Castanon said she wanted to speak out in the hopes of getting her attacker off the streets. She believes if he's done it once, he'll do it again.

She added that she wants to help make sure what she says happened to her doesn't happen to anyone else.

"We don't want to have another generation of young women growing up, fearing walking the streets by themselves," she said.

The suspect is about 20 to 30 years old, 5-foot-6 to 5-foot-8, about 225 pounds with eyeglasses. Anyone with information is asked to contact Crime Stoppers at 800-577-TIPS.

NYPD

SEXUAL ASSAULT HELP: The National Sexual Assault Hotline at 800-656-HOPE (4673) provides 24-hour help to people who have experienced sexual assault or know someone who has.