You are able to bait a pursuit if you are wanting to do a bank. Below is the bullet point from the NON-RP rule in general rules.
Baiting Government Services without proper IC motive. (For example, bank robbers have IC motive to bait police if they want to get their attention away from the bank they are wanting to rob).
In relation to the topic, I believe there should be an IC or OOC protocol for LEO's to camp banks. There should be sufficient reasoning, like an active trace on a wanted individual with an affiliation, or intel of a gang about to hit a bank. By no means am I saying "cops can camp banks if there's a reason". Instead, one or two units should alternate in patrolling the area, as if there is a failed bank attempt say in the city, other banks are going to be on high alert, so would make sense for some form of police presence patrolling the area.
Cops however, should not be able to sit outside a bank ((Tabbed Out)) doing paperwork or doing whatever else they may be doing, as like mentioned above, restricts our already demotivated criminal player base.