I personally feel that that T and the diamond should only be used if you have a death wish. Are they simple enough for even the most retarded guy you work with to do, yes but that is no excuse to use piss poor tactics. If you've been to MOUT training thats similar to what you should be doing for an active shooter response instead of a forming a big line of guys in the middle of a hall to shoot at. You'd want to form up in a formation that provides less of a target for the BG. I'd go into greater detial but this is still an open forum plus I think this section is readable by other parties in the profiles.

Have I ever heard of a sleeper in a actie shooter... No but I do feel that you are getting good training. It's more of a terrorist type thing to do and that kind of attack is very possible!

Hey I noticed you were in an active shooter forum. I have a few questions if you don't mind me picking your brain. I'm a Military Police Officer stationed in Hawaii right now, used to be Texas. We're going through active shooter training this week. The instructor was teaching us that going through a building with a 4 man team to use the "T" method. Three officers line up in the front, and the fourth pulls rear security. How accurate is that based on your training? He said it was that or the diamond formation.
My next question is they're pushing hard for "sleeper" shooters in our training and scenarios. I've tried to research a real life active shooter with a sleeper shooter that waited for LEO contact before becoming activated but came up empty handed have you heard anything like that? Thank you in advance for your time and knowledge.