From bainbridge island, you are more than likely hearing transit on the west seattle tower, which the sheriff does not use unless a unit were in the seattle area, which is not likely. You would need an external antenna, preferably pointed toward tacoma, orting or buckley to get the public service stuff, and i'm not sure you could even hear it then from your location. My 536 in the car, (with the exact antenna and coax that my buddies have on their patrol cars) is hit and miss at best when i'm mobile. No sheriff south of nisqually or north of auburn at all.
On the other hand, my bench mounted 436 recieves ALL sheriff and the newly RR listed charlie fire bank superbly but i have a roof mounted Yagi 700mhz pointed to the orting tower, and that only became audible when i went to the high dollar low loss coax (75' to the antenna) rg type coax produced nothing.
I live smack dab in the middle of pierce county, and had to spend damn near as much for an antenna, mount and coax as i did for the radio.
Also as a side note, I talked to a friend at a lunch meeting today who is a south sound 911 supervisor and he related there are still "bugs" and getting alot of flak from the troops for what it is worth.