John Malleus

 is the chief scientist of Vault 92.

He is in charge of implementing the experiment of Vault 92 and is initially intrigued and optimistic about the results of the test. When the killings begin, however, he quickly gets to the bottom of the situation and discovers that Rubin has been brainwashing the musicians without controls or safety measures, turning them into violent, primal animals.

Appearances
This character is mentioned in Fallout 3 but does not actually appear in the game.