By Andrew Goldsmith ( June 23, 2017, 12:28 PM EDT) -- When special counsel Robert Mueller began his work last month, he may have been surprised to learn the Ninth Circuit had added a new element to one of the potential crimes within his jurisdiction just two days before his appointment. In United States v. Olson, the court held that misprision of a felony requires a defendant to know the crime he or she is concealing is a felony.[1] Apparently, no other court has considered the possibility of such a requirement in the 227 years since the crime was codified. Despite this critical change, Olson gives little guidance on how to prove, for example, that a defendant knew that a private citizen could be sentenced to more than a year in prison for corresponding with a foreign government to influence that government or to undermine the United States. The potential implications are not limited to cases under the purview of the special counsel's office. In cases involving low-level or little-known underlying felonies, this new element may convert the most widely applicable obstruction statute, carrying among the lowest sentences for such a crime, into the most difficult to prove....