The Ninth Circuit remanded this case to the BIA to determine whether a conviction for failure to register as a sex offender in violation of California Penal Code section 290(g)(1) is a crime of moral turpitude. The BIA in this case had held that it categorically was a CMT pursuant to its decision in Matter of Tobar-Lobo, 24 I&N Dec. 143 (BIA 2007).
After its decision, however, the Ninth Circuit issued a contrary decision regarding the Nevada sex offender statute, finding that it was the underlying sex offense and not the failure to register that constituted a CMT. See Plasencia-Ayala v. Mukasey, 516 F.3d 738 (9th Cir.2008).
The Attorney General also issued a decision casting doubt on Tobar-Lobo. The AG's decision in Silva-Trevino held that an offense must have some level of scienter (criminal intent) to qualify as a CMT. California penalizes failure to register even if it is due to mere forgetfulness, which is in tension with the requirement that a CMT have an element of intent (at least of recklessness, rather than mere negligence).
Read the opinion at http://www.ca9.uscourts.gov/datastore/opinions/2011/05/11/07-71988.pdf