Under the Adam Walsh Act of 2006, only certain criminal actions will prohibit USCIS from approving a petition on behalf of a fiancée. They are as follows:
(A) an offense involving kidnapping, unless committed by a parent or guardian;
(B) an offense involving false imprisonment, unless committed by a parent or guardian;
(C) solicitation to engage in sexual conduct;
(D) use in sexual performance;
(E) solicitation to practice prostitution;
(F) video voyeurism as described in 18 USC § 1801;
(G) possession, production, or distribution of child pornography;
(H) criminal sexual conduct involving a minor, or the use of the Internet to facilitate or attempt this conduct;
(I) any conduct that by its nature is a sex offense against a minor.
If you have not been convicted of such a crime, merely being on probation is not going to prohibit approval of the I-129F Petition. If you were convicted of such a crime, you will have to demonstrate clearly to USCIS that you do not pose a risk to your fiancée despite the conviction. If you believe the Adam Walsh Act applies to your situation, I would advise consulting a knowledgable immigration attorney.
Answered on Mar 21st, 2012 at 4:08 PM