Mister Lopez

 is a 65-year old suicidal resident of Rivet City.

He can be enslaved with the slave collar.

Background
According to the Fallout 3 Official Game Guide, his wife and child were killed by Raiders, and he has fallen into a depression ever since. This is probably the cause for his suicidal behavior.

Unmarked quest: Suicide Watch
Lopez considers committing suicide due to the fact that no one remembers him or even cares about him (also learned by talking to him on the Flight Deck that he couldn't save his family.), but he doesn't have the courage to do it himself. The player can either help him find a new purpose in life or push him over the edge (literally.) If you wish to do so, be on the deck of the ship at 3 pm.

You can find him at top of the ship, but you'll have to enter through the stairwell and from there go up the stairs and you'll find a door that has a sign on top that says "Bridge Tower". Once you enter inside go up the small stairs and as you walk out turn to your left or right (Depending on the position of your screen). You'll find a sign that'll say "Marketplace". Once you have located the sign you'll see some stairs. Go into the hall then go up stairs and repeat the process 3 times til you enter a room that only has one door. Once you are in that room enter it and you'll be at the highest point of Rivet City. If you see the ledge, that is where Mister Lopez will be. Make sure you don't fall with him, though; it might result in crippling both legs, or worse, death.

Bugs

 * Lopez's hands bug into Deathclaw claws on occasion.


 * If you jump into the river as you shoot a Mini Nuke straight in the air (facing him), Mister Lopez will teleport into the water above you alive if done correctly on the Xbox 360.
 * He has been found outside Vault 101 in the beginning of a new game, on his way to Rivet City. (Unconfirmed)
 * Sometimes you are unable to speak to him. If so, just wait a few hours or days. Go back, he will now speak to you (Confirmed on Xbox 360)

Behind the scenes

 * Mister Lopez is a reference to the Oblivion expansion pack The Shivering Isles, where an NPC, Hirrus Clutumnus asks you to kill him, one of the methods being to push him off a tall structure.

Appearances
 only appears in Fallout 3.