I was able to listen to Mesa today to confirm some channel usage with addresses and officer call signs. I also researched the police division names online as there appears to have been some division name changes over the years.
Mesa Police refer to their dispatch talkgroups by channel number. Below are the talkgroups, channel numbers, and associated "Police Divisions".
3000 - Ch. 1 - Fiesta Police Division
3003 - Ch. 2 - Central Police Division
3006 - Ch. 3 - Red Mountain Police Division
3009 - Ch. 4 - Superstition Police Division
Each police division also has a "Talk" channel that is encrypted. I have not heard officers refer to these with channel numbers. They always just say "Go to talk" when they want another officer to switch to the talk channel.
3001 - Fiesta Police Division Talk
3004 - Central Police Division Talk
3007 - Red Mountain Police Division Talk
3010 - Superstition Police Division Talk
If I had to guess, they would have "decks" like Phoenix using the ABC selector switch on radios. A Deck might be Dispatch, B Deck might be talk, and C Deck might be HOT. Next time you see a Mesa PD officer in a restaurant over lunch, look at the display on their radio and let us know how they are displayed.
Maps and more information on Police Division can be found on the City of Mesa website.
City of Mesa : Departments & Divisions
I am still confused on the usage of Mesa HOT talkgroups that the DB has listed. If anyone can help clear these up, that would be very helpful.
3002
3005 - DB shows this as NOT Encrypted
3008 - not in DB, fits into talkgroup numbering
3011
3014
I will update the DB with better descriptions for Mesa PD channels.