I don't want to waste my degree, I'd readily sacrifice visible tattoos to go further up, and it'd be silly for me not to.Depends what you do in the police though doesn't it? My friend Martin was in the police force and he had tattoos up both arms. But he wasn't a policeman as such, he was a manager in the control room.
If you don't come into contact with the public, you've got a better chance of being let off I guess, but you'll always be a bit limited.
And there's still a small element of the 'old boys brigade', my mum still encounters it (she's been there since it was normal to ask the women officers to make the tea and get biscuits- think like Life On Mars, that's pretty close. She's only got where she is by being hard as nails (harder than some of you! ) and whiter than white), so it's better not to give them any excuse to pass you over...