He was actually the fourth member of the gang, impersonating a cop.

Makoto's bicep stung as the "cop", who was actually a member of the gang in disguise, snapped one half of a pair of handcuffs onto her right wrist, while continuing the painful grip on her left arm. She thought desperately what to do . " I can't have a criminal record ! It'd be awful. Just imagine of my friends found out. Usagi would never let me forget it . Oh! the humiliation .And I'd be the laughing stock of my community . First, I've got to keep my name out of it. " My name is Haruka Ten-oh" . she said. Might as well see how Sailor Uranus handled a little embarrassing publicity.