There seem to be quite a few transwomen in the police nationally, though most are in non-public facing roles as much to protect them than cis women.
Whilst it's possible to recognise some transwomen, I know someone who's transitioned MTF at 20 and is now in her mid 30's; outwards looking at her and listening to her, you'd never know she was trans; for all intents and appearances looks 100% female.
The question that crosses my mind is how you identify if the person a police officer or airport security searching you is a transwoman or a cis woman, whilst I accept that in many cases you might be able to recognise someone is transgender or cis,, many transwomen it's impossible to differentiate gender.
Should there be a common sense rule that there not allowed to search cis women?