As of that time, it's difficult to pinpoint a specific individual as "the youngest psychopath in history" because diagnosing psychopathy in children is a complex and controversial matter.
Psychopathy is typically diagnosed in adulthood using standardized assessment tools like the Hare Psychopathy Checklist-Revised (PCL-R). However, there is a related diagnosis called Conduct Disorder, which is a childhood-onset disorder characterized by persistent patterns of behavior violating the basic rights of others or major age-appropriate societal norms. Some individuals with Conduct Disorder might display psychopathic traits, but it doesn't necessarily mean they will develop full-blown psychopathy as adults.
It is essential to remember that mental health diagnoses should be made by qualified professionals using proper assessment methods. It is inappropriate and unethical to label children as psychopaths based on their behavior alone.
If there are any specific cases that have emerged after i lost interest in that topic, I would not have information about them.