Theo was 22 years old and worked as quartermaster on a probationary contract which earned him 35 Caps per mission. He was recruited to fill the ranks after the death of Dallas and Kira. Shortly before his death, he desired a mapping mission, so Reilly led him and the rest of the team out to Vernon Square. He died after a Frag Grenade was thrown by a Super Mutant into the stairwell he was in.
|This character is deceased. ()|
|This character is involved in quests.|
- Unlike all other members of the group, he wears a Merc charmer outfit instead of the Ranger Battle Armor.
- The code for the ammo box is always "Reilly9090." Its contents are 200 5mm Rounds, 100 5.56mm Rounds, 100 10mm Rounds, and 4 Frag Grenades. They can either be kept, or shared with the rest of the Rangers, on the roof of the Statesman Hotel.
Theo appears in Fallout 3.
- Ranger compound terminal entries; Reilly's terminal, current personnel listing, Theo
- Ranger compound terminal entries; Reilly's terminal, Reilly's personal notes, Personal Entry 176
- Ranger compound terminal entries; Reilly's terminal, Reilly's personal notes, Personal Entry 179
- Lone Wanderer: "Where is Theo's body?"
Reilly: "We lost him on one of the stairwells on the second floor of the Statesman Hotel. He almost made it, but one of the Muties hit us with a frag grenade; blew him apart. If you can get to his ammo crate, there's a ton of rounds inside. Bring as many as you can to the Rangers."