Not sure this is a good idea: electing "police and crime commissioners" in England and Wales
(Except for London.) See "Labour announces police commissioner candidates: Seven former ministers including Lord Prescott are among 41 Labour candidates for police posts in November elections" from the Guardian. The concern is that the positions and policing get (more) politicized if the leaders of the service are elected, and that maybe the concern for professionalism is downgraded.
In May, voters in 9 large English cities defeated proposals to begin to elect mayors. Bristol did vote in favor of electing a mayor, and another community, Doncaster, voted in favor of retaining the mayor as the top elected official in their community. See "Cities vote against having elected mayors" from the Guardian and "Nine cities reject elected mayors" from the BBC.