How can someone be schizophrenic AND in sufficient command of their mental capacities to be culpable for their actions?

JEFFREY DAHMER/ANDREA YATES Serial killer Jeffrey Dahmer was thought to suffer from paranoid schizophrenia but his bid for a not-guilty-by-reason-of-insanity verdict failed. Essentially, the jury accepted that he was schizophrenic but that he was still culpable for his behavior. Similarly, Andrea Yates, who drowned her five children in the bathtub, was purported to be schizophrenic by one of the courts […]