Here is some info that might help.
Under the Petty Offense Exception, a noncitizen is automatically not
inadmissible if:
s/he has committed only one crime involving moral turpitude, ever; and
s/he "was not sentenced to a term of imprisonment in excess of six months (regardless of the extent to which the sentence was ultimately executed)"; and
the offense carries a maximum possible sentence of one year or less.FN315
Thus, a person convicted of a misdemeanor first-offense Crime of Moral Turpitude with a sentence of six months or less is not inadmissible under the moral turpitude ground, but the person is inadmissible under this ground if the sentence formally imposed exceeds six months in custody.