For anyone locally or passing through, don't dismiss k band warnings as being real. DPS mainly uses ka band, but they still have k band handhelds that i have come across around Phoenix and in Tucson.
From a distance it looks like a Kustom HR-12, but i'm not positive.
I came across one in Phoenix, and on several occasions i've come across them being used in Tucson and on I-19, south of Tucson.
Mobile and stationary.