It is illegal to possess or detonate a weapon of mass destruction.

The Law

Just in case federal terrorism laws weren't enough, Utah enacted its own specific state statute making it a felony to build, possess, or deploy a nuclear, chemical, or biological weapon. The law was drafted during a wave of post-9/11 security overhauls to give local prosecutors jurisdiction over terror threats. Simply put, building a dirty bomb in your basement is a severe violation of the state penal code.