Smile! Thief on candid camera

A SUBWAY MUGGER who snatched an iPhone from a young woman in lower Manhattan was caught on surveillance video sporting a big grin moments after the crime, cops said Saturday.

Police hoping to wipe that smile off his face released the video and asked the public’s help identifying and finding the crook.

The 19-year-old victim was about to step off a downtown 6 train that had just reached its last stop at the Brooklyn Bridge/City Hall station when the perp grabbed the phone about 11:15 p.m. on Oct. 24.

The suspect, who was standing on the platform, grabbed her iPhone as the train doors opened and ran off before she even stepped off the train. The teen had boarded the train at Union Square, cops said.

The surveillance video, taken a few minutes after the crime, shows the suspect leaning over a turnstile to shake hands with someone he recognized at the station, police sources said.

The suspect is black and between 18 and 25 with brown eyes and black hair. He was wearing a gray hat, black jacket, black shirt, black jeans and black shoes.

Police ask anyone with information on the suspect’s whereabouts to call Crime Stoppers at (800) 577-TIPS. All calls will be kept confidential.