Randall Guiterez was one of the vault residents of Vault 95.
Unlike the other residents, Randall was not an addict but an observer placed in the vault by the Vault-Tec Corporation to monitor the residents and the experiment of that particular vault. His primary duty was to observe the other vault residents and ensure that they stuck to their rehabilitation program. After five years had elapsed since the vault had been sealed, he opened a hidden stockpile of chems within the vault and in order to observe the various reactions of the residents when they discovered it.
There are no terminal entries to indicate what happened after he opened the hidden stockpile.
Randall Guitierez is mentioned only in Fallout 4.