don't read this post unless youre bored. it's old and no longer relevant. starting dec 31, 2010, your criminal background check has to be done via the fbi, so go to this website and get your paperwork started:
http://www.fbi.gov/hq/cjisd/fprequest.htm
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i started this process 3/10/09. during this process, my visa expired, my extention expired, and my request for a second extention was denied. i had to leave korea. i went to japan for a day and came back as a tourist. i havent worked in 3 weeks, y'all!
so this is how i got my visa the slow way:
as of 12/15/07, would-be teachers must submit a criminal records check (CRC) AND a health certificate with E-2 visa appplications. The health certificate can be done at any hospital i think. For the CRC: get an fbi or state CRC, or a local police check/report from your city/state of residence that shows a statewide criminal record (this is also called a letter of good conduct, or GCL or Good Conduct Letter it's all the same). I did the former. had i to do it over again, i'd have done that latter, getting the letter is much faster.

to get my background check, i first had to get an official fingerprint card. click
here, fill out the form. tell them that you're a teacher in Korea needing to renew your visa and ask them to send you the california fingerprinting cards.
<---this is what the finger print card looks like (thank you
google image search). i think it was under 2 weeks that i got it in the mail (they sent 2 blank cards to me in korea).
once you get the card, fill out everything in english and go to police station to get fingerprinted. bring a translator. i went alone, and luckily one woman there spoke english.
MAYBE the police will be confused as to why youre there, as were my local police dept. B/c these laws are new, many dont know what is needed and blah blah blah. Anyway, they looked at my arc card and passport, then pulled out the ink, printed me, and sent me on my way. they didnt ask to keep a copy or anything at all. i think this is strange b/c how does anyone know those are MY prints? there's no proof i did it AT the police station, i couldve printed my neighbors dog, who's going to find out? i dunno. maybe these visa laws will be tweaked in the future.
the prints cost $32 to do, they'll take a money order in US dollars or personal check (drawn fm a US bank). the cost of the GETTING the money order was almost 20,000 won at my korean back, so i had my pops send me a check in the mail.
i sent the fingerprints, a $32 check, and a letter saying i need the cbc b/c im renewing my E-2 Visa. in the letter, i asked for an offical seal/stamp and signature, but i still got a shitty copy that korean immigration rejected. i wrote another letter, included the "good" sample below, and got a "good" cbc in the mail 3 weeks later. if youre in the midst of this process, print and attach the sample below w/your request.
then i took the the background check to the american embassy here in korea to get an
affidavit. this is sort of the same as having it "authenticated." the embassy doesnt authenticate anything, instead you go in and sign a paper promising the cbc is real. they gave me a copy of that paper, and i turned in that, the cbc, my passport, my uni degree, and uni transcripts to my job, and they'll get me a new visa number. once i do, ill have to leave the country and come back, this is called a "visa run." THEN i can go back to work.
Had i to do this all over again, i wouldve done the cbc with the police dept, its much faster. read about it
here.
a shitty background
check and next to it, a better, more official looking background check: