Visionary serial killers suffer from psychotic breaks with reality, sometimes believing they are another person or are compelled to murder by entities such as the Devil or God. The two most common subgroups are "demon mandated" and "God mandated."
David Berkowitz in the summer of 1976, started a shooting spree that terrorized New York City for an entire year. Armed with a .44 caliber, he shoot 14 people until his arrest, killing 6 of them. He was also notorious for sending strange, bold letters promising future killings to the police. He is a classic example of a visionary killer, as he was found to be driven by his inner hallucinations: He claimed that his neighbors dog was actually a demonic entity that encouraged the killings, and that he was also possessed by the demonic entity at some point. He was diagnosed to have paranoid schizophrenia, a disease that is often associated with visionary killers. This is because often times the hallucinations and delusions those associated with paranoid schizophrenia face encourage them to act in socially-maladaptive ways, in extreme cases causing them to murder others.