Going to the department website they have a link to the Twitter account being used here
* The British Police have their own .police.uk domain space.
* The ip address is used for shared webhosting and is owned by uk2.net
whois does say "West Midlands Police", but this could be forged.
Either way it's extremely unprofessional and will be shut down by a lawyer soon :)
http://www.west-midlands.police.uk/np/birminghamwestandcentr...