Are we all capable of killing? Insight brings you up close with people who have killed as part of their job. Soldiers, police officers and executioners are recruited and trained to be able to kill. Pulling a trigger or administering a lethal injection may only take a second, but the effects can last much longer. Almost every species has a resistance to killing its own kind, and many psychologists believe humans have a built in aversion to it. Some killers are trained using dehumanising language and brainwashing to minimise empathy for their targets. Others – including one of our guests – received barely any training at all. Insight hears from people who have been trained to kill, and looks at what draws them to this sort of work, how they are trained, and the impact it has had on their lives.