Weeks after the assault, the NYPD released the surveillance video to the public, seeking help identifying the assailant, seen following the victim down the stairs, repeatedly punching and kicking her, throwing her to the ground, and emptying out her purse while she's down. When she gets up and tries to flee, he briefly chases her.
As reported by Huffpost, shortly after Gawker posted the surveillance video on Tuesday night, a commenter on the site posted a link to Aidan Folan's Facebook page, calling Folan the "most likely suspect."
On his Facebook page, Folan is seen wearing a black hoodie with the Greek letters "Alpha Phi Delta" on the front and "Stugotz' (Italian slang for "balls") with the number 27 on the back.
The unsub in the surveillance tape had "Stugotz" emblazoned on his sweatshirt.
A fraternity brother outed Folan to the police.
Posters to Folan's Facebook page called him a "worthless fuck", a "coward" and an "asshole loser".
On Wednesday, the 21-year-old Folan was arrested in the city for assault and robbery.
According to NBC New York, Folan lives [with his parents Estelle and Lorcan Folan at 440 76th Street] in Bay Ridge.
The Daily News reported that Folan was a  graduate of Bay Ridge's highly-regarded Xaverian High School, where he was apparently a varsity diver.
According to Folan's Facebook profile, he graduated from St. Francis College in Brooklyn with a degree in broadcast journalism, but according to the New York Post, he dropped out of St. Francis after a year.
Although his Facebook profile says Folan worked as a counselor at the Center for Family Life in Sunset Park, the New York Post reported he was just an intern there.
Folan has one prior arrest, for marijuana.
Folan has been released on $50,000 bail [Gothamist.]
The Alpha Phi Delta fraternity was founded by Italian-American students at Syracuse University in 1914 [New York Post.]