Smile!

A Philadelphia teenager who authorities say used a stolen cell phone to snap a photo of himself that automatically got sent to the victim has turned himself in.

Eighteen-year-old Kadeem Cook turned himself in around 11:30 p.m. Thursday.

Cook is the main suspect in an armed robbery on Oct. 7.

The victim's cell phone was taken during the robbery. The 20-year-old woman had programmed her phone so that it would automatically send photos to her home computer.

Some time after the robbery, she received a photo of a young man holding a large handgun to his head.

After the photo was released, the gunman was identified as Cook and an arrest warrant was issued.