The main characters are John, who is the manipulative one, and the woman he targets. John is this character who has a whole set of false personas. The woman, on the other hand, is just an ordinary person looking for love or connection. Her family members are also significant as they react to the situation, some trying to protect her, some being deceived as well.
In 'Dirty John based on a true story', the central figure is Dirty John himself. He is a complex character full of deception. Then there's the female lead, the victim of his schemes. Her family also plays important roles. They are initially skeptical of John but then as he weaves his web of lies, they too are caught in the chaos. There are also friends and acquaintances who either see through John or are also duped by him.