This story is getting national attention for 2 reasons. There was an innocent bystander (cops were innocent too but I'm speaking in terms of police ambushes) and because the shooter was black.
It's an unfortunate truth that police ambushes and attacks on officers are are not uncommon. You don't here about most of them unless the story took place in your local news area.
This story went national because it plays into the "police vs black people" narrative that allows the media to milk tragedy for ratings. Why did it take so long for so many outlets to pick up the story is the so called narrative is a big as the media would like you to believe?
The real issue is the gun problem in America. The shooter's motive is just one of many behind gun violence in the W.