It seems to be both safe and effective, police in making person encounters need to do two things:
1) They need to develop rapport in order to maximize the effectiveness of their investigation. They need to be friendly, relate to the person, and make the person feel comfortable, trusted, and understood. This is regardless of whether the person is a criminal, a witness, or whatever. They need to adapt their personality to the person in question.
2) They need to remain cautious and "switched on", lest they make themselves tactically vulnerable and end up far down the reacting side of the curve in the event that the person, or a third party, decides to become hostile. This involves maintaining proper interview position, and so on.
I've done a few roleplaying training scenarios where I've seen myself fail on either of these issues. It seems pretty easy to be "switched on" and be a robot professional. It also seems easy in many cases (although requires skill and experience in general) to connect with people and basically develop a temporary perceived friendship. But I'm finding that it is hard to do both. It is very easy to get mentally submersed in the latter mindset and very quickly end up letting your guard down, dropping your hands, or taking a vulnerable position. It strikes me as very human. When developing rapport with someone, we naturally do things like mirror them and show physical signs of openness.
It seems to me that this creates a dangerous switching dynamic. You're either in one mode or the other, and in either case you're probably working extremely sub-optimally. Moreover, the switch can't be thrown quick enough when it has to be.
Instead, it seems that one has to show all the outward signs of (1) while maintaining all the inward mindset of (2). This is something which seems totally contrary to nature, as demonstrated by the fact any cop with enough experience can read a person's inner mindset off their outward physical actions.
For those with experience, do you have any tips on how to develop and maintain this elusive simultaneous state?