How would an atheist convince a serial killer not to be a serial killer?

[Mister Agenda]

If one is an atheist and believes that there is no God and no afterlife, then if a serial killer wanted to spend this life harming people because that is what he claims makes him happy, how would you convince him not to do this?

Sure, he may have to fear being sent to prison for his crimes, but it is possible he could simply avoid the law. Therefore, the implication of atheism is that if a person wants to spend their life harming people because they claim this is what makes them happy, there is no reason not to do this.

What's the Christian track record on curing serial killers? Serial killers often exhibit structural deficits in their frontal cortexes and temporal lobes. Not sure how to convince someone out of a 5% reduction of gray matter in the limbic system, reduced metabolism in the prefrontal cortex, and damage to the orbital cortex.

I wouldn't try to convince a serial killer to stop, I'd call the cops to stop them.