The term "tweaker" technically refers to a stage within the methamphetamine abuse cycle. From the State of California Resource Center, publication No. (ADP) 99-2455 (link):
The most dangerous stage of meth abuse is called "tweaking." A tweaker is an abuser who probably has not slept in 3-15 days and is irritable and paranoid. Tweakers often behave or react violently and if a tweaker is using alcohol or another depressant, negative feelings and associated dangers intensify. The tweaker craves more meth, but no dosage will help re-create the euphoric high, causing frustration, unpredictability, and the potential for violence.
A tweaker can appear normal: eyes can be clear, speech concise, and movements brisk. But a closer look will reveal the person's eyes are moving ten times faster than normal, the voice has a slight quiver, and movements are quick and jerky. Tweakers are often involved in domestic disputes and motor vehicle accidents. They may hang out at raves and parties and participate in spur-of-the-moment crimes, such as purse snatchings and assaults, to support their habit.
Detaining a tweaker alone is not recommended and law enforcement officers should call for backup.
Do we have any stats on this? I didn't think that meth was a big problem in davis? -George Lewis
Yes, it's hardly unheard of. - MichaelGiardina
Oh, what demons these tweakers are! In fact, sounds like an undercover cop - ChristopherMckenzie
Some statistics: the Davis Police logs http://cityofdavis.org/police/log/press/ from 04/01-09/27/2005 list three meth incidents. However, all three were reported during the past few days (09/24-09/26), which seems unlikely. Maybe they drop reports from the online logs? RAND corporation seems to have *very* detailed stats about drug abuse http://ca.rand.org/stats/health/drug.html — does anyone have access? JoFeuerstein
That log only has data for reports filed in the past week. —RyanCastellucci
See Methamphetamine for a list of Meth House busts in California including Davis. They are sorted by county.