He got away the first time but when the victim and police got together they came up with a plan to call the stolen phone and talk to the man who took it.
"The suspect didn't know that he was talking with the police," Sgt. Mike Wagoner said. "(They) dickered over the price for the phone and so when the suspect did show up the police obviously where there to meet him."
They arrested him after he tried to run he tripped and fell face first onto the ground.
It apparently didn't occur to Westerfield to wonder how the "buyer" got the phone number when he didn't yet know it himself. Link -via Gizmodo