My own sense is that police are largely immunized to the severity of gun laws - they're carrying guns legally, no matter what, and aren't "more careful" just because public carry is more illegal.
That said, I tried to find some evidence for or against your correlation, and the below link is a list of a sort of 'mass shooting' (in that multiple officers opened fire); many are from NYC and LA, but there could be a correlation with just having a higher density of officers locally responding to an incident before opening fire.
And in many cases the deaths of suspects - er, victims - is not by bullet wound, but the victim is still dead. I'm going to sound like a one-trick pony here, but while the tool is of significance, the police mindset toward "suspects" is the root issue.
Edit: forgot the link, here:
https://en.wikipedia.org/wiki/Contagious_shooting#Examples