Riverhead pd operates on the suffolk county 800mhz trunked radio system. Yes for the time being the bc15xt will work. Once they are moved to the new 700mhz system then that scanner will not work as the new system is a p25 phase 2 digital system
Non public safety users are going to start being migrated over to the new system come sometime this spring. Public safety will be the last users to be switched over. As far as scanners any scanner that is capable of p25 phase 2 tdma. The one issue is depending on your location you may have difficulty listening due the system being simulcast and the scanners not handling simulcast very well.
Did Riverhead and Suffolk ever come to an agreement? Last I read, Riverhead and some other east end departments were not included in the counties upgrade. Was there a more recent story than this from 2014?