If you're raised to kill - are you wrong?
It's a good question. The parents are definitely to blame from a moral perspective, but society still has the problem of the killer they raised. At some point in life we all have to be held responsible for our own actions, even if there is conflict about when that point is or should be. You have given an extreme example of a killer, but your question really applies to indoctrination generally. In fact, there is greater incentive to address your own actions with the given example because killing is ubiquitously agreed to be wrong. But what if your indoctrination was into a religion or political ideology? You might realistically live out your entire life without ever being forced to address it.