Who operates these? I saw four completely unmarked, all white trucks, running code 3 out of Las Vegas, southbound on HWY 95 near railroad pass. The first one sort of looked like a fire dept. rescue squad type, the next one was a pickup truck, then another, smaller squad type, then a pickup pulling a fully enclosed trailer- also all white. They had plenty of lights and sirens were blaring, couldn't identify who was driving and no decals or markings of any type. Didn't look like the FD haz mat unit or Metro's bomb squad but I am curious.