Miller's assassin

An assassin was responsible for killing McDonell Benedict Miller at his Alaskan home, in February 2005. Liquid Snake later posed as Miller three days later, during the Shadow Moses Incident.

Unconfirmed history
The assassin managed to cross treacherous terrain without a vehicle, evade the surveillance cameras before cutting the security system's power, silence one of Miller's huskies mid-howl, and then leak seuvofloraine gas into Miller's home. Miller prepared himself to attack the intruder, but was outsmarted by the poison gas, succumbing to it despite his best attempts to escape.

Behind the scenes
The assassin is indirectly mentioned in Metal Gear Solid, but is not identified. Given Liquid's later impersonation of Miller, it is possible that he was involved in the hit.

In the Raymond Benson novelization for Metal Gear Solid, the killer's method of assassination was elaborated on in the third chapter. Miller's comment about the assassin having similar skills to Solid Snake in order to pull it off implied that it may have been Liquid Snake himself.