Gruesome slaying rooted in 'core issue' Dismemberment cases rare, haunting JAMIE DUFFY | The Journal Gazette Killers who dismember their victim's bodies are often motivated by vindictiveness, a forensic psychologist says. “It's likely there's some emotional connection, some relationship that went bad and it can be anything, but it's got to be a real bad feeling, tremendous rage, anger. This person might feel disrespected in some way, but a person who does this has a core issue,” Dr. Charles Heller, a forensic psychologist based in New York City who has spent 40 years testifying as an expert witness in court cases, said this week during an interview.