Proximity is the space between each person in the room. Does it increase or decrease between subjects upon entering domicile? Dispersement can be indicative of escape (every man on his own), grouping can indicate attack. Does proximity indicate territory? A move to a spouse can be marking territory especially if there's contact, touching, hand on shoulder, around waist, on knee.
Encroachment is the proximity between yourself and the subject that becomes encroached by gesturing, pointing, but without contact. For many in the process of escalating (sometimes just in the fraction of a second) they'll test the space between you with an open hand, palm up directed towards your sternum, or a pointed finger directed towards your face, to elicit a response.
Invasion is when contact is made, the palm hits your sternum, the finger pokes you. Retreat if there’s still a possibility of de-escalation, restrain otherwise. But, again, you know this.
Screening is where the subject stands between you and the victim. They may move with you as well as you try to assess the well-being of the victims. Reverse the rolls and the victim may be trying to protect their attacker. No room for assumptions here. Time to increase the space that exists between all of you.
