This arrest stems from bribes he received for his campaign fund in exchange for attempts to assist in import of illegal weapons from foreign countries.
According to the affidavit, Yee was actively helping undercover employee of FBI connect with an international arms dealer to bring illegal firearms in to the US. Yee was fully aware of the legality surounding such act and even asked for a cut in arms sales as well as saying the transaction has to be made after he becomes the Secretary of the State. He was fully aware of the origin of such firearms, so far as to say that they are from MILF(Moro Islamic Liberation Front) who are waging war against Phillipine government.
Yee is currently out on $500,000 unsecured bail and is expected to plead not guilty.
Affidavit
http://cbssanfran.files.wordpress.com/2014/03/complaint_affidavit_14-70421-nc.pdf
For related parts, see p.25, p.67, p.80 - 102
Sources:
CBS - NBC Bay area - L.A. Times
