TULSA, Oklahoma - A witness helped Tulsa Police track down robbery suspects after a teenager was beaten and robbed in a Tulsa park. Police have three suspects in custody and are searching for a fourth.

A 16-year-old male was alone in a park near 10800 East 41st Street when he was robbed just after 5 p.m. Thursday, police records state. Police said four males - one armed with a handgun - walked up to him and made small talk then started punching and kicking him.

Police said the robbers took the teen's iPhone and left in a car. A witness got the tag number and called it into police. Officers tracked the vehicle to a house in the 10800 block of East 34th Street and arrested three males.

One of the suspects is 16 and was not identified by police. The other two are Esau Lopez and Isai Lopez, records show. Both are 18.

Police said the victim had injuries to his face but refused medical treatment.