Criminals, especially the most evil, psycho SOB's, do train. Some 30 years ago, I watched a training film of surveillance film of San Quentin outlaw biker bangers training to take away guns from cops.
A Huntington Beach, CA cop shot an killed one of two Aryan Brotherhood bangers who were doing an armed robbery. I watched the training film of it. The two dirt bag bangers were not only well trained, they were using their training on the cop. He immediately recognized what they were attempting to do (distract him preparatory to murdering him). In the ensuing gunfight, the HBPD cop killed one of the bangers. The other escaped & subsequently arrested and charged with the felony murder rule & armed robbery. He's probably still in either Corcoran or Pelican Bay, which is where he belongs.
But for the HBPD cop's professional training, knowledge of professional defensive firearms training and tactics, and knowledge of dangerous criminals, his name might be on the Peace Officer's Memorial at Washington, D.C.
In my opinion, being able to immediately assess abilities of a threat is as important as tactical firearms.
At the beginning of summer of '18, I saw an EME banger in a Suburban So Cal city. I ID'ed by tats. He was proud of his EME tats. Nope. I wasn't armed. But there were many cops around who had assuredly ID'd him and FI'd him long before I saw him. He was probably on S&S, so cops probably, at least, Terry frisked him. An EME banger is trained and will fight to the death of either himself or a good guy.
If you can view any of LAPD Captain Rich Wemmer's officer survival videos, jump all over it. Captain Wemmer was an expert's expert on officer survival. His interviews of cops who survived shootouts provided incredible live-saving knowledge. I'm sure that every law enforcement training facility in the nation has Rich Wemmer's videos in their libraries. BTW, I am darn near 100% certain that that video of the HBPD cop who survived the gunfight with two AB bangers was a Captain Wemmer production.