That's how I started. With the same department that EMTRN's with now. Used to be able to do reserve after only 40 hours of training. POST just changed the minimum for reserve / part time to 80 hours. Either way, it's still a lot less than the required hours of training for full-timers. I think the SCSO academy was 560 hours when I went through, IIRC. Been a little while. Most departments around here have a reserve program.
Yep, POST just recently changed that, too. Now you can only work 6 months before you gotta hit an academy. Not really an issue if the new officer is riding with an experienced officer. Some places would scare the h*ll outta me, though. Some small towns will hire someone and cut them loose on their own to enfore laws with little to no training until they got sent to the academy. THAT is scary!