Re: They know, you know
That's part of the problem, but the real problem is that nobody is BOTHERING. If you delete at the police station those systems inform the central police computer. But if you delete from the central computer, it just lets all the copies of that data (why are there copies anyway?) linger around and orphan themselves with no central control.
The problem is not "we don't know how". The problem is "we put in too many different systems that it's a hassle to do".
To be honest - my brother got into his 40's without a passport or driving licence or any other formal photo ID. He has bank accounts and everything normal, but he only has a birth certificate and a range of information to provide as identity.
He certainly has a national insurance number but that's hardly ID (take note America, SSN's are NOT ID!). But can you really imagine someone being briefly arrested and then immediately being able to provide national insurance numbers etc.? I can't. I can't even imagine that such an ID is even useful - if I give you my NI number, would you be able to tell me where I'm living? Not with certainty. I don't inform ANYONE at NI when I move house, unlike DVLA, etc. Do I have to login to some portal and provide NI to actually do anything? Not really.
The closest we have to actual ID is the government gateway (which used to issue individual client certificates but is now just username/password). That lets me renew driving licence, passport (even change the photo), file tax returns, etc. so it's pretty central and integrated. But we don't use that for anything like that - the closest is when you have to get one of those codes from it where the DVLA certify who you are so that you can hire a car.
And I think we're now scrapping GG, aren't we? I know there's been talk of it. The ID card debacle basically put the nail in the coffin of central integrated services.