Being a sex offender is probably a crime of moral turpitude, right? What about the acting of failing to register as a sex offender? The U.S. government thought so; that's why it initiated deportation proceedings against Khalid Mohamed, a citizen of Sudan. Mohamed was convicted of sexual battery in 2010, and in 2011, he failed to register as a sex offender. Finding these to be a conviction for "two or more crimes involving moral turpitude," the government said he had to go, and the Board of Immigration Appeals agreed.
The Fourth Circuit Court of Appeals wasn't so convinced. It ordered Mohamed released on September 29, and provided the reasoning for its order in an opinion released October 17.