Ed Mireles discusses the FBI Miami Firefight:



Solid first hand account.  For me the second half of the interview had the most meat.  I knew or guessed a lot of this, but was great hearing it directly from Ed.  

Ed discusses the importance of training and mindset.  As far as people keeping shell casings after gunfights... whatever happened at Newhall, that is a real thing.  With bad training, goofing around with casings happens in actual firefights.