[You Gotta Be Kidding Me]

Simple answer -----

The cops are lazy and not very smart. The sniper(s) could (and probably did) paint their white van blue, or switch vehicles, altogether. Of course, this would NEVER occur to our squad of "Andy Taylors and Barney Fifes".

[Clara Lou]

The cops are lazy and not very smart.
Is that your expert opinion? It's just so easy to sit back and criticize when there's no pressure on you personally.

[johnny7]

The cops are lazy and not very smart.

I don't think they're lazy but they are just paid hacks who want to give out citations and retire.

The worst nightmare for them is come across this dude/dudes in the act.

So far, all they can do is call an ambulance and target white vans.

They pray he moves into some other state.

[sweetliberty]

I am more inclined to think that the only connection of the sniper to a white van is that he is waiting until there is one in the areas of his crimes and that is his cue to shoot.

[Mr. Mojo]

Of course, this would NEVER occur to our squad of "Andy Taylors and Barney Fifes".

Barney for sure, but Andy was a decent cop. Here's who we really need.

[CyberAnt]

"cops are lazy and not very smart"

Well ... I guess that shows what you know!!

[willyboyishere]

Even simpler answer: LACK OF IMAGINATION.