A jury has retired to deliberate its verdict in the trial into the alleged murder of Sue Addis.

Pietro Addis, 19, is standing trial charged with murder after killing his grandmother at her home in Cedars Gardens, Brighton in January, 2021. He admits manslaughter but denies murder.

After the jury heard evidence over the course of more than a week, they will now consider whether or not to convict or acquit the teenager.

Summing up the evidence, Judge Christine Laing KC told the jury that psychiatrists disagreed on whether or not Addis was suffering from psychosis at the time of the killing.

The Argus: Pietro Addis is standing trial accused of murderPietro Addis is standing trial accused of murder (Image: Sussex News and Pictures)

Dr Peter Misch, instructed by the defence, believed Addis suffered from a "relatively brief and transient paranoid psychosis" which "substantially impaired the defendant's ability to form a rational judgement".

Judge Laing added that Dr Misch believed that Addis's “delusional belief that his grandmother wanted to kill him” was the driving factor in the killing and argued that this made the teenager fearful and that he was "acting because of his mental disorder".

Dr Duncan Harding, instructed by the prosecution, added that the killing was "clearly an incredibly shocking incident" but that Addis’s experiences prior to the killing "weren't consistent with him suffering a psychotic breakdown".

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Dr Harding agreed that Addis "had had some psychotic like experiences", but in one interview where Addis described hearing the voice of rapper Biggie Smalls, he said people who hear voices were "often scared of them" but that Addis "didn't give that impression".

The court heard evidence that Addis had a “delusional” belief that his Mrs Addis was trying to kill him, but the prosecution argue that “Pietro was not in fear of his grandmother”.

The Argus: Sue Addis was found dead in January, 2021Sue Addis was found dead in January, 2021

Mrs Addis, 69, was found stabbed to death in her bathroom and her grandson, then 17, was arrested at her home where he was also living at the time.

A popular restaurateur, Mrs Addis ran Italian restaurants in Brighton and Hove including Donatello in The Lanes and Pinocchio in New Road.

Mrs Addis was described as a “warm and generous person who was very supportive of her family” in written statement from friends read in court.