NEW YORK (WABC) -- A suspected thief who sucker punched a stranger on the subway before stealing his cell phone was arrested Tuesday. The entire incident was caught on surveillance camera.Police arrested 31-year-old Leonard Johnson and charged him with robbery.The attack happened at the Times Square subway stop early Monday morning.Police say Johnson approached the 35-year-old victim at the turnstyle just after midnight, spoke to him briefly and then punched him without warning.The suspect then forcibly removed the victim's cell phone from his hand before fleeing on foot toward the northbound No. 1 train platform.