http://www.northwestradio.net/interceptnw/
Seattle uses trunked. digital and in many cases switches to cell for supervisor calls and “sensitive” traffic.
I don’t have a scanner at the moment but trunked scanners can get pretty expensive last time I checked. Some interface with a pc to match up both sides of a conversation.
http://www.usascan.com/files/scancat2.html
Info specific to King county is localized here:
http://www.northwestradio.net/interceptnw/king.htm
These are trunkgroups rather than specific frequencies.
Seattle (Seattle simulcast)
3216 SPD Citywide ATG (patch ID?)
3248 SPD West
3280 SPD North
3312 SPD South
3344 SPD East
3408 SPD Data
3440 SPD Tac 1
3472 SPD Tac 2
3504 SPD Tac 3
3536 SPD Tac 4
3568 SPD Event 1
3600 SPD Emergency
3632 SPD East Tac
3664 SPD South Tac
3696 SPD North Tac
3728 SPD West Tac
3760 SPD Inv Tac 1
3792 SPD Inv Tac 2
3824 SPD Ctr 1
3856 SPD Ctr 2
3888 SPD Cmd 1
3920 SPD Cmd 2
3952 SPD Cmd 3
3984 SPD Cmd 4
4016 SPD Cmd 5
4048 SPD Cmd 6 Harbor Ptrl
4080 SPD Narc 1
4112 SPD Narc 2
4144 SPD Narc 3
4176 SPD NTF
4208 SPD Vice 1
4240 SPD Vice 2
4336 SPD Emer Rsp Team 1
4368 SPD Emer Rsp Team 2
4400 SPD Hostage Neg 1
4432 SPD Hostage Neg 2
4464 SPD Internal Invest
Details on just what a trunked system is and is not can be found here.
http://strongsignals.net/access/content/new_user.html#SEC12