There aren't enough content warnings in the world for the story of Ed Kemper and Herbert Mullin, two serial killers who simultaneously stalked Santa Cruz in 1972 and 1973.

Kemper posed as a wanna-be cop and Good Samaritan to lure hitchhikers into his car and do horrific things to his victims. Mullin believed his murders were human sacrifices to prevent earthquakes. Their paths eventually crossed.

This episode, clinical psychologist Dr. John Meigs joins us to talk about how to stop the next Ed Kemper or Herbert Mullin. Both men have been diagnosed with the same mental illness, and we discuss whether better detection and treatment of serious mental illness in this country could prevent mass killings.

We can't stress enough that most people with mental illnesses will never behave violently. As Dr. Meigs explains, they're far more likely to suffer a stressful and difficult effort to manage or overcome the situation. Illnesses don't discriminate, and any of us could suffer mental illness. So we need to remove the stigma attached to seeking help.

But Kemper and Mullin are extreme outliers. And the failure to diagnose and treat similarly dangerous people could be calamitous. The mental health group the Treatment Advocacy Center reports that "at least one third of mass killings are carried out by individuals with untreated serious mental illness" -- a finding that cries out for better treatment.

We talk this episode about whether our current emphasis on punishment over prevention makes sense.