This guy should be fired. Not just for his actions in the abstract, but because anybody who thinks they could actually get away with something like this is quite obviously insanely stupid.
FIRED? Indeed, if they don't prosecute, lock his ass up, strip him of and and all pension and benefits and require him to register as a sex offender for the rest of his life, then whatever huge settlements this city pays for police misconduct from now to eternity are noting more than their just desserts.