Before the Omaha and Colorado shootings even happened, several of the other instructors at my range and I, along with a few "pro-citizen carry" LEOs spent a lot of time discussing what would be some of the key things to cover in a CHP class when discussing shooting to defend a third party. We came up with the following as the key items to cover.
Obviously, you could get far more detailed than that. But, we had to bear in mind that a lot of people taking a CHP class aren't doing it for any more reason than to make it less complicated to transport their firearm legally in the state. So try to give them enough to make them realize that there is a lot more they need to learn, but not so much that they can't retain most of it.
1. Avoid drawing your firearm unless you are absolutely certain of
your target. Drawing prematurely has two hazards. First, you've
identified yourself as a target yourself, both to the shooter and to anyone
without adequate restraint to identify their target before shooting.
Second, if you aren't certain of who needs to be shot, you probably will
hesitate when it really counts.
2. Don't assume that seeing someone shooting a gun means that they are
the shooter. If you can't see who they are shooting at, you just may
be pulling the trigger on the citizen that actually stopped the
3. Don't expect verbal commands to work. If you do, you probably
won't fire when the shooter decides to just shoot you instead of comply.
If you must give the shooter a chance to surrender, don't say anything
until you are behind rifle proof cover. Otherwise, the two most likely
situations to happen are that you die, or you both die. There are
multiple examples of this over the last few years.
4. If the shooter is dead, your best bet for not being shot by the
police is to have your firearm on the ground and your hands behind your
head. Obviously, this isn't always possible. But the better you are at
appearing non-threatening and compliant, the more likely that they
won't shoot you. Remember, it is fairly likely that the only report 911
received is "man with a gun shooting people at [random place]". They don't
know that you aren't the shooter.