It's a fair point, but I will say the graveside stunt appeared to be nothing more than an attempt to manipulate his supporters.
I should have used his letters to CC to illustrate
Those weren't an angry text message sent in a heat of the moment, he had time to think about it, put himself in Colins shoes and decide not to send it. The nasty bile that was sent when his attempts at manipulating CC failed was designed to be as hurtful to Colin as possible and I have little doubt that Bamber enjoyed the thought of causing him pain.
I'm pretty sure that attempts at manipulation and a desire to hurt others, perhaps relishing in their pain registers on the psychopathy scale but admit, I am no psychiatrist.
Psychopaths get pleasure from being sadistic; they enjoy inflicting pain — it excites them.
But not all psychopaths become murderers, few do, in fact. Many can lead seemingly normal lives, in fact, very successful ones. Tycoons are often psychopathic and the reason they get so rich is that they’re ruthless and don’t care who they hurt while they tread on everyone to get where they want.
Jeremy Bamber was prepared to kill his family so the twins would never inherit a share, and he also wanted the money without waiting possibly 20 years or so. That shows how ruthless he is. He also displayed sadistic tendencies as a child when throwing stones at baby ducklings and hitting little animals with big sticks: it made Sheila cry and he got pleasure from that too.
He got pleasure from tricking June into putting her hand in his pockets he’d hidden rats in.
Pleasure from cycling round and round June then pulling up sharply.
He later got pleasure from psychologically abusing his girlfriends. He’d raise their hopes, then let them down. Flirt with others in front of them. Play mind games. Make them feel worthless and dependent on him. And he’s still doing it now. He uses the majority of women who write to him, pretends he fancies them, and then starts asking for money. He got pleasure by allowing Daisy to travel all the way to visit him, just so he could see her crestfallen face as he spat “I never liked you anyway!”
He’s as evil and psychopathic now as he was when he murdered his family: he’s just learned how to hide his deep hate because he realises it doesn’t benefit him.