In by far the biggest "crimmigration" case of the year, the Ninth Circuit has invalidated the definition of a crime of violence under 18 U.S.C. 16(b), finding the phrase "substantial risk" to be unconstitutionally vague. The court relied on the Supreme Court's decision this summer in Johnson v. United States which invalidated the similarly worded residual clause of the Armed Career Criminal Act (the residual clause refers to crimes that involve a "significant risk" that force will be employed) on vagueness grounds.
You can read my blog post on Johnson here: http://www.sabrinadamast.com/journal/2015/6/26/supreme-court-invalidates-the-acca-residual-clause-disavows-the-ordinary-case-test
The full text of Dimaya v. Lynch can be found here: http://cdn.ca9.uscourts.gov/datastore/opinions/2015/10/19/11-71307.pdf