http://www.bbc.co.uk/news/uk-18327642
Most of the data requested there is already held by UK police forces, it's just a matter of collating and displaying it securely. And vetting hundreds of low-paid civil servants/temps. And... it would be a bloody shambles, wouldn't it?
Not a bad idea, but you know it'll cost close to a billion in real terms (rip-off consultant fees before project even begins, inevitable BS budget quote from idiotic private company, inevitable payout over the wrong data given out...).