Mystery surveillance aircraft in skies of AZ

Can anyone tell me what type of surveillance aircraft are in the skies of Arizona nightly? I know they are extremely quiet, manuverable, and fast when they want to be. They land every morning between 4 and 4:45 A.M. at Sky Harbor. They have turbo fan engines and alot of lights.

my guess is a preditor. proboble flying the boarders.

i think i remember a story that they were doing that now.

Predators do not have turbofan engines.

Best way would be to look at flightaware.com for that time period and for KPHX