That is where you run into problems with defense attorneys. There are other problems with how you get the evidence. Because getting a search warrant is as hard as locking somebody up legally. It's based on probable cause. All these things have to be articulated and it takes a long, long time to get a search warrant.
Detectives can get it in like three or four hours, usually on overtime.
Bosses don't like that. In your books they always want to track some murder victim's credit card receipts and it turns into a big civil liberties issue. Yeah, that's a very big thing. You're not allowed to do that. But that's why they have to go to sleazy Bob Hurley the private eye.