Please explain the huge guys dressed in black with automatic weapons in this video

VIDEO Hombre vestido de mujer abusaba de pasajeras del Metro
Está casado y es ingeniero en sistemas, tiene 46 años y en sus ratos libres se vestía de mujer para subir a los vagones exclusivos para mujeres y cometer sus delitos sexuales

The poor guy got arrested for getting on the women-only subway cars in Mexico city and touched several women on the butt. It's fine that he gets arrested, but what the hell is the deal with the guards and having the guy put on the wig. I say they shoud drop the charges, he's been punished enough.