A teenager sobbed in the dock today as he heard evidence about the days before he stabbed his grandmother to death inside her home.
Pietro Addis, now 19, is on trial accused of murdering popular restaurateur Sue Addis, 69, at her £1 million Brighton home on January 7, 2021.
He has admitted to killing her, but denies the murder. Today the Lewes Crown Court heard how close the two were before Mrs Addis’s death, at which point Addis collapsed.
She sobbed with her head down before wiping away her tears.
The Addis legal team claims he was suffering from a form of psychosis when he entered his grandmother’s bathroom and stabbed her 17 times as she lay in the bathtub.
He then changed his clothes and called the police to ‘turn himself in’. The 999 call was played to the jury earlier in the trial. It said: “I’m calling to turn myself in. There’s been a murder.”
Footage of the Addis arrest shows him expressionless and giving monotone responses to police.

Sue Addis, 69, owner of Brighton restaurants Donatello and Pinocchio was stabbed to death
Dr Duncan Harding, the prosecution’s consultant child, adolescent and adult forensic psychiatrist, said: “Her speech was calm and measured, with no evidence of an euphoric mood or pressured speech.” There was no evidence of thought disorder or any other psychotic phenomenon.
He said video footage of his arrest 20 minutes after calling police showed that he could answer questions in a “rational” way.
“It’s important because we can see how Pietro presented himself,” he said. “If he had been psychotic at the time of the murder to the extent that it would substantially impair his ability to control himself, we would see the effects of that on video.”
He said that cases of ‘transient psychosis’ would last a few weeks or months.
“It doesn’t last 20 minutes,” Dr. Harding said: “It lasts for weeks or months and you would see evidence of it in this video and we don’t see evidence of it.”
The video shows Addis answering monosyllable questions before finally saying, “No comment.”
Dr Harding said: ‘He answered questions in a reasonably lucid manner. He was in shock.
“If Pietro had been psychotic to a degree that could in any way explain the incident, I would expect to see signs of that psychosis present an hour later, and in fact, the next day, I don’t find him suffering from a mental disorder or any mental disorder at all. the time of the incident.’

The murder occurred at the home of Ms Addis in Brighton on January 7, 2021, during the third lockdown.
He said he found no abnormal mental function that could explain Addis’s behavior.
Dr Harding said: “If this murder were the result of a psychotic breakdown, I consider it extremely unlikely that Pietro would have had the presence of mind to call the police and give his name and say that there had been a murder.”
He said: I find that this tragic murder occurred in the context of anger. It does not seem appropriate to me to claim a psychiatric defense of diminished responsibility in this case.
Mrs Addis owned the Brighton restaurants Donatello’s and Pinocchio’s, which are among the most popular in the complex, attracting celebrities including actor Bill Nighy, Katie Price, Michelle Collins and a host of Premiership footballers.
The court previously heard that Addis was taking a catalog of illicit and prescription drugs prior to the January 7, 2021 murder.
In addition to regularly smoking cannabis, the teen also took cocaine, ketamine, and MDMA.
He was also taking Xanax, an antidepressant, and Adderall (an ADHD medication), as well as Elvanse, a medication he was prescribed to treat his ADHD.

Addis moved in with her grandmother after an argument with her father and stepmother
The catering student was also raiding his grandmother’s medicine cabinet and taking her breast cancer drug, Letazole.
In his defense, the jury was told that the catering student was suffering from “psychosis” at the time of the attack.
The court heard that the psychosis was “transient” and he recovered a short time later without treatment or medication.
During cross-examination, Dr. Peter Misch, a psychiatrist for the defense, said Addis’s psychosis stemmed from a mistaken belief that his grandmother was going to kill him.
Dr. Misch said that killing her grandmother may well have alleviated her psychotic symptoms.
He said: ‘Her psychotic symptoms then subsided. I formed the opinion that he was psychotic and that the psychosis was relatively brief and transient.
I was forming the opinion that it was a transient psychotic period. It lasted a short time and resolved without medication. Transient psychosis is defined within the psychiatric classification system.’
But Dr. Harding noted that he was in his right mind to change into clean clothes before the police arrived.
“If someone was psychotic to the point of not being able to control themselves and not knowing what they were doing, I have a hard time seeing how after that event they would have the presence of mind to change their clothes.”
The court heard that Addis’s behavior had deteriorated in the months leading up to the murder.
The teenager had dropped out of college and reported to work at the family restaurant and was described as “depressed, paranoid, despondent, anxious and worried.”
The court heard that Addis’s family felt that the deterioration in his behavior was due to his use of both illicit and prescription drugs. Her family was so concerned that they flushed her prescription ADHD medication down the toilet.
After a heated argument with his stepmother in December 2020, the teenager was sent to live with his grandmother in Withdean, Brighton.
A little over a week later, he armed himself with a kitchen knife, entered the bathroom as his grandmother lay naked in the bath, and stabbed her to death.

Pietro Addis, now 19, has admitted to killing his grandmother but has denied the murder and is on trial at Lewes Crown Court.
The court heard that in the days before the incident, Ms Addis had been seeking psychiatric help for her grandson.
She had searched the internet for a psychiatric evaluation for her grandson at Ticehurst Priory, Kent.
The court heard that Addis had trouble controlling his anger, often resorting to punching walls or himself.
In the days before the alleged murder, Ms Addis told a friend that her grandson had been acting “strangely”.
He had started knocking on his grandmother’s bedroom door at night telling her that he loved her.
The trial continues.