The worst part is that one cop fired one round, hitting his partner and saying nothing about it. Which caused thewounded cop to draw, shove his sidearm into the other guy and firing 4 rounds.
Attempted murder on part of #1 shooting cop and conspiracy to murder and murder charges against both.
Nemo
If we must charge them based on current government law, I'd say manslaughter for both. Cop #1 says the suspect has a gun in error, cop #2 rightfully attempts to shoot a guy gaining freedom showing the potential to do harm that he thinks has a gun. He shoots #2 cop who then thinks he was shot by the suspect. Failing to get him back under control after being shot once already, cop #2 attempts to end the threat with shots through the suspects back.
The #2 cop was a victim of his own poor communication and cop #1's poor weapon training, with a shot to his gut. The suspect was also a victim of the poor communication.
Communication is the most vital and also the most fragile in a gunfight. I suppose this qualifies as such.