Yes, the presidential advisors tell Jed Bartlett that he can't use the military as assassins because of the Posse Comitatus Act. That's pretty ridiculous. The Posse Comitatus Act prohibits using the U.S. military for law enforcement, which is no what Bartlett was ordering. It's not the Posse Comitatus Act that was relevant -- it's the laws against murder! As far as I know, sending out a hit squad is illegal under the laws of the District of Columbia (where the order for the assassination originated), the United States (a federal offense because the assassins traveled internationally to carry out the hit), and Bermuda (where the assassination took place).

--- Steve