Killing a person is not humane, even if the criminal is not humane. What is humane is subjective to a person’s upbringing, education, beliefs, and religion. Therefore different people interpret what is humane differently. For instance, some people consider putting a pet asleep is humane if the animal is in great pain, but doing the same thing for a person is often not considered humane. Other people would not kill an animal even for food. In some cultures, mercy killings are honorable.