The court had also heard how Schreiber visited his father’s grave in Stalbridge, Dorset, and sent pictures of himself “raising a glass” to his memory on the anniversary of his death, hours before the attack.

On April 6 2021, Schreiber texted his sister Rose: “Raising a glass to Dad who passed away 8 years ago today. RIP. You remember right? Your real father David, not the one who “bought you” who you call your father … cupboard love.”

Rose reminded him it was the next day. Then, on the actual anniversary of his father’s death, Schreiber sent the same picture of the gravestone to a friend and said: “I have a mixture rage, sadness and calm reflection.”

Schreiber went to visit his father’s grave in St Mary’s church in Stalbridge, and he sent his brother Adam one picture of the gravestone and another of him raising a glass with the message: “Happy anniversary dad, miss you and your wonderful presence so much.”

Later that evening he attacked his mother and Sir Richard.

The jury was played rambling voicemails left by Schreiber minutes afterwards. He left a message to his friend Josh Adamson, telling him: “I’ve killed my mother and I’ve killed her partner.” Mr Adamson called his mother Ava, who was the first person to call the police.

‘You’re a liar and a gold digger just like your mother’

Schreiber apologised to his brother, Adam, and said: “I’m going to die now and I hope you understand why that is… It’s over for me now and it’s over for my mum and it’s over for Richard.”

A final call, to his sister Rose, said: “You’re a fantastic sister even though you’re a liar and a gold digger just like your mother.”

After that call, Schreiber’s girlfriend, Sathia Pagliuca, received a notification that she had received £30,000 with a note saying “Love from Thomas”.

She texted him asking “what have you done?” and “I cannot have all this money” before speaking to him on the phone, but when he hung up and she could not reach him again she rang the police.

The jury was shown bodycam footage from armed police, with one man describing the scene as a “warzone”.

The prosecution said Schreiber repeatedly stabbed his mother and Sir Richard after contemplating their murders for months.

Schreiber has admitted manslaughter over the multimillionaire’s death but denies murder. Regarding his mother, he pleads not guilty to attempted murder.

He has also pleaded guilty to dangerous driving on the night of the killing, after he fled in a Range Rover and was captured by police after a high-speed chase and a “hard stop” in London.

The trial continues.