http://en.wikipedia.org/wiki/Moral_turpitude
If you go to the above link and find the word "web site" after US State department's - I think this link gives the definitive answer on what is considered to be moral turpitude:
Interpretation of Moral Turpitude
The actual definition of moral turpitude is a lot narrower than many people think, and there is a full definition available for immigration purposes from the US State department's web site. The following is based mainly on material from that source.
http://www.travel.state.gov/visa/visa_1750.htm l
http://www.law.cornell.edu/uscode/html/uscode0 8/usc_sec_08_00001182----000-.html
Exception Clause (i)(I) shall not apply to an alien who committed only one crime if�
(I) the crime was committed when the alien was under 18 years of age, and the crime was committed (and the alien released from any confinement to a prison or correctional institution imposed for the crime) more than 5 years before the date of application for a visa or other documentation and the date of application for admission to the United States, or
(II) the maximum penalty possible for the crime of which the alien was convicted (or which the alien admits having committed or of which the acts that the alien admits having committed constituted the essential elements) did not exceed imprisonment for one year and, if the alien was convicted of such crime, the alien was not sentenced to a term of imprisonment in excess of 6 months (regardless of the extent to which the sentence was ultimately executed).
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