"if the police get access to your email account, they can force a Apple ID password reset"

That's an interesting assertion. I mean, yes, sure, they could do that, but it's an interesting question of whether they are legally allowed to do that. Effectively they'd be misrepresenting themselves to your email provider and to Apple as if they were you. Is that acceptable 'undercover policing'? Can they reset your banking password too? Can they do this only while they have you under arrest?