My old web gear has a 30-round mag pouch that doubles as a first-aid kit. That thing has a triangular bandage, two compress pad bandages, gauze 3x3's, gauze roll, tape, anitbiotic ointment, tweezers, a triangular razor blade and a wire saw (for splint making).
The big car-kit is an
M-3 Medic's bag with a lot of additional supplies including Kelley forceps, scalpels and suture needles.
Now... with this said pointed out... in the aftermath of a shooting situation, it is unlikely that I will use the kit to treat the person(s) who just threatened my life. This is especially true if I need the kit to treat myself, loved ones or those who were with me.
Circumstances may also dictate that I'm too busy trying to keep my head, preserve the scene & evidence, etc. to render aid. Which means I may let someone else use the kit to render 1st aid if practical.