Flashlight: I always have one on my gun belt but not all officers do, AND “two is one; one is none.” Better to have it and not need it rather than needing it and not having it. Today’s high-output (125+ lumens) LED lights are lightweight and compact in size. There’s no reason not to have one in your go-bag.
Personal IFAK: Because YOU have to take care of yourself throughout any engagement. If you get injured, whether it’s by gunshot or broken glass, YOU have to tend to the injury and then either get back in the fight or (if it’s a debilitating injury) extricate yourself as you can. Any fellow officers with you cannot stop to nurse you or give you care. They have to stay in the fight/hunt. IF you find yourself uninjured at the conclusion of hostilities, you then have the ability – to the level of your medical training – to assist the injured caused by the bad guy(s).
Door stops: During searches it often becomes necessary to secure doors in some manner. Door chocks are quick and easy to use. If you can’t search a room, in a non-active-shooter scenario, blocking it shut behind you is the next best thing.
Spring-loaded window punch: This is on my “because you just never know” list. There are windows all over the place in our world, and remember we’re not just talking about schools. Safety glass and tempered windows are harder to break than you might think and a window punch solves the problem pretty quick.
All surface black magic marker: For marking rooms, doors, closets, etc. as you clear them, or with numbers of casualties found inside (God forbid). Reality is that you never know what you’ll need to communicate to those coming in behind you and this simple tool makes it easy to leave information as you pass.
So, that’s my Basic Police Go-Bag. What have I left out that you’d include in yours? Your comments are welcome.