Most Meridian Law TGs are encrypted and can't be monitored. No one has submitted specific Meridian Law TG info to be added to the database, although they may be dispatched by Ada county on Ada county TGs. The best thing to do is monitor all Ada county unencrypted TGs (TG 1000)and see if there is any Meridian traffic.
Meridian fire is dispatched by Ada County Fire 1 on TG 1400 and vhf 155.385. You should monitor all Ada county fire TGs as Meridian Fire may also use other TGs for response and operations, although I don't know which TGs specifically.