If a person pulls free and runs away from a police officer after the officer has grasped his arm and told him he is under arrest, under PC §38.06(a) [1], he has not esacped from custody. Escape can occur only after an officer has successfully restrained or restricted a suspect -- that is, when the officer's grasp has amounted to an arrest.  Warner v. State, PD-1644-06 [2].