Legal Question in Criminal Law in California

Yes, if you knew the drink was poisoned and if you intended for it to be stolen and then consumed. Setting a trap like this would be a crime even if the thief does not die; it just wouldn't be murder. Even if the thief doesn't take the bait, setting the trap would qualify as an attempted murder. The nature of the charges would depend upon what happened to the thief and what the defendant expected to happen.

In other words someone dies from drinking a poisoned can of soda with your fingerprints on it, and all you have is a BS story about how they stole it from you. See you in 25 years-to-life.

yes. When you poison a drink, the risk someone you don't expect will be killed is part of that crime. The fact the wrong person drank it, is totally irrelevant.

this is a hypothetical ... homework assignment, right? I hope so. ;)

Mr. Fleetwood makes an excellent point. My earlier answer presumed that the drink had been used as bait to catch (and kill) a thief. It is also possible that the drink was intended for one person but stolen and consumed by another. In that scenario, the poisoner would still be guilty of murder under the doctrine of transferred intent, since the death would be the result of his intentional actions and would be the kind of harm he intended to cause.

The situation is like a gunman who misses his intended victim and kills someone else instead. He would still be guilty of murder even though the person he killed was not the one he was trying to kill. The situation you describe is slightly different because the person who died was a thief, but that distinction is not enough to negate the poisoner's guilt.