"Non Lunatic" seems to be accurate to me. He is discerning targets by only firing on police. This displays method. Police are also hardly harmless. And have a reputation for instigating and encouraging violent situations.
There is one major difference between what is reported in the news now, and what we know as a typical crazy guy with a gun.
There's no targeted location. He didn't attack a school, stadium, theater, police station, city hall. Which would be one of the first points on news released. The shooting was in an outlying subdivision of the city, hardly a "target rich" area.
The fact is that no one, including us seems to know the context of what happened. This would decide whether he's a murderer.