TUCSONAZ.GOV LETS YOU DO THIS ONLINE!
This will take you directly to the online service on the tucsonaz.gov website.
OR, CALL or EMAIL:
You can contact the City of Tucson's Graffiti Removal Program by phone at (520) 792-City (2489) or email at email@example.com. More information is on their website: http://tdot.tucsonaz.gov/graffiti