Almost without exception, law enforcement agencies never want to shoot from one apartment blindly into another apartment. One of our major design concerns was to make sure that a missed shot would lose the bulk of its energy in a partition wall between apartments and pose as little threat as possible on the other side.
In this demonstration we fire the Maxstop I.R.P. round into the typical minimum building code standard partition wall between multi-family units which consists of two sheets of 5/8" fire rated gypsum wall board on each side of a stud. We have left out the fiberglass insulation normally found in this type of wall as it offers no ballistic resistance. This "one-hour fire wall" is also used to separate offices and businesses as well.
As you can see, the round penetrates the wall but lacks the energy to break our glass backstop ten feet away. It would be unlikely that anything more than very minor flesh wounds would be inflicted at that distance.