We don’t really know how aware he was that they were cops. Breonna Taylor died because her boyfriend didn’t know they were cops.
Sure, this could just be a survivalist whacko taking his last stand once the gubmint finally came for him, but it also could be triggering someone’s fight or flight when they’ve surrounded themselves with tools for fighting and a fearful mindset. And again, a cop got shot. They should do stuff to avoid that.