A teenager has been jailed for stabbing his grandmother to death in her bath.

Pietro Addis, then 17, stabbed prominent businesswoman Sue Addis 17 times at her house in Cedars Gardens, Brighton, in January 2021. A jury heard he was suffering a “brief, transient, paranoid psychosis” at the time.

Addis, now 20, admitted killing his grandmother, 69, but was acquitted of murder after a jury found he had diminished responsibility.

A statement from Mrs Addis's sons read to Lewes Crown Court today said: "The biggest punishment for him is knowing what he has done.

Addis's uncles added: "We want him to have a go at life and Mum would too."

During the sentencing hearing, Sarah Elliott KC, defending, said: "He retains their [the family's] full love and support not withstanding what has happened.

"It is obvious that this offence has inflicted the most enormous hurt on the Addis family. All of Sue's children have come together in providing information to the court to support him."

After hearing from the prosecution and defence, Judge Christine Laing KC remarked that "it is the greatest testament to her [Mrs Addis] that she leaves behind loving and understanding children and grandchildren".

However, she continued: "It was a choice made by you to use and abuse those drugs [cannbis and Elvanse, an ADHD medication] and had you not been doing so then it is highly unlikely that your grandmother would have lost her life in this appalling manner."

During his trial earlier this year, Addis was found to have suffered from the “delusional belief” that his grandmother wanted to kill him.

A post-mortem report found Mrs Addis died due to multiple stab wounds to the neck and chest.

The Argus: Pietro, then 17, on police bodycam footage from the night of the incidentPietro, then 17, on police bodycam footage from the night of the incident (Image: Sussex Police)

Mrs Addis was a popular restaurateur who ran Donatello in The Lanes and Pinocchio in New Road, Brighton.

During the trial, she was described as “a warm and generous person who was very supportive of her family” and who “spoke about her family with affection”.

Mrs Addis was also known for her charity work including with The Argus Appeal, Martlets hospice and the Rockinghorse children's charity.

Judge Christine Laing KC sentenced Addis to 15 years in prison, made up of ten years in prison plus a five-year extension.