[jacquesm]

Replying to my own comment after thinking some more about this: It also explains to a large extent the choice of gas for the murders. After all you can open a gas tap a long way away from where the people are that you are going to kill, in fact the person opening the valve may not even know what they are doing (unlikely in this case, but still you could easily arrange it that way).

Everybody else is just doing their job right? Herd a bunch of people into a room, remove a bunch of corpses from a room. Nothing to do with killing anybody, or so you could delude yourself.

This also ties in with why I'm so totally against drones, robots and other kinds of remote warfare (including aerial bombardment), they make it so much easier to pretend you're not killing real people.

[elcapitan]

To be complete there: They didn't use gas from a tap, they used Cyclon-B, a cyanice pesticide which comes in cans, which is solid and becomes a gas when it gets in contact with air. They put it in from the top through the ceiling.

I think beginning with that point all the killing and removal work had to be done by groups of prisoners.

As for drones: Yes, there was an interesting keynote talk at 33c3 by a former us army guy who has become a whistleblower. They hire specifically for gamers to become drone pilots, because they already have that abstraction from their games. They see the bad guys (arabic looking people) on their screen and have less issues to hit the trigger than a pilot who would be based in the area.