This shows evidence of a cultural shift in society.
Years ago, tattoos were the strict property of armed forces personel, who had usually obtained them while drunk, or criminals, who got some done in prison, and often added to them afterwards. Thus, tattoos were generally seen as a mark of the more 'rough and ready' members of society, although i stress that I am talking entirely in generalisation terms here, and would not wish for a moment to appear to subscribe to such basic sterotyping.
Within the last generation, tattoos have become far more popular, and as such, are well on the way to losing their implied status as badges of potential bad behaviour.
In order to fully embrace such a change, we need to accept that a tattoo these days does not (and indeed never did) evidence a propensity towards anti-social behaviour - and therefore their appearnece on people such as police officers should not infer anything other than a personal preference for body art.
During the current 'crossover' phase, which will last about 10 - 20 years, some people will object, but eventually tattoos on police will be as accepted as pierced ears on stockbrokers.