One very famous case where handwriting analysis helped in understanding and knowing more about a serial killer is zodiac killer.
Zodiac killer who is an American serial killer who is believed to have murdered at least five people in northern California between the years 1968 and 1969.
The murders were a subject of intensive investigation and media coverage, particularly because of the killer’s taunting letters that he wrote to newspapers and the phone calls that he made to the police.
His letters were signed with a symbol resembling the crosshairs of a gunsight and typically began with the phrase, “this is the Zodiac speaking.”
One of the handwriting trait in his handwriting that helped to know more about him is Maniac D.
Maniac D trait can be referred to as maniacal behaviour. This trait shows that the person has no control over his hand movement which further means that he has no control over his or her emotions. These kind of individuals show explosive behaviour. The more it occurs in one’s handwriting the more it indicates that the person loses his control.
Therefore this personality trait can be one of the major reasons why he committed such gruesome murders.