It was not a note. It was a phone message.
The sniper left a note and asked them to put a certain phone number into service (maybe a phone number the sniper will easily remember or the phone number spells something out). The cops have now put the number into service and it is working as a direct link to maybe Chief Moose. They are letting the sniper know that his request has been done and it completed. Now they want him to call. --brigette