Hart, now 21, is one of five people on trial for the 2017 murder of Valentin Vermeesch, a mentally handicapped 18-year-old whose body was fished out of a river in April 2017 after he was reported missing for a week.
The group of five kidnapped and cruelly tortured their victim him for hours, and he was later thrown into La Meuse while he was still alive, but hand-tied.
The report says Hart is capable of manipulating and twisting reality to achieve his means and to convey a positive image of himself.
Hart, who was 19 at the time of the events, is also described as being “unable to show empathy” and capable of " making others appear responsible for his own actions.”
“There are no affective or social traits in him,” one psychiatrist reportedly said during the hearing. “His malice is manifest and impulse-driven.”
Hart, who exhibited violent behaviour and an “explosive personality” throughout his childhood, was prescribed medication in 2007 to “control his aggressive impulses," according to French-language daily Le Soir.
During the trial, ongoing for two weeks, it was recently revealed that Hart, alongside fellow-defendant Belinda Donnay, had already cruelly mistreated another victim.
The Brussels Times