I wonder if you're actually receiving an encrypted channel or have reception issues. Since you specifically mentioned Sacramento Sheriff, I must assume you're monitoring them on one of the two trunked systems. Can you be more specific as to the system and talkgroup(s) you're speaking of?
Happy New Year
There are four new, fairly active encrypted channels listed for Sacramento Sheriff in the database. They simulcast on both sites of the Motorola system, not on the P25 system. Only SSD has access to these channels, including their rotor-wing and fixed-wing aircraft.
14160 - "Encrypted 14" (secure alternative/replacement for Tac 4/Mode 14)
14192 - "Encrypted 15" (secure alternative/replacement for Tac 5/Mode 15)
14224 - "Encrypted 16" (secure alternative/replacement for Tac 6/Mode 16)
14992 - Unknown use, but radio IDs on that channel indicate may be SED related.