A man found guilty of killing his date in a speedboat accident was not interviewed under caution because of a “mistake” by police, the Court of Appeal has heard.

Jack Shepherd was jailed for six years over the death of 24-year-old Charlotte Brown, who was thrown from his boat when it capsized on the River Thames during their first date in December 2015.

The 31-year-old web developer is now challenging his conviction for manslaughter by gross negligence.

His lawyers told a hearing in London on Thursday that he was initially interviewed as a “significant witness” rather than a suspect, and therefore was not afforded his rights to be cautioned and to have a solicitor present.

Stephen Vullo QC, for Shepherd, said the court will have to decide whether the interview caused “unfairness” and therefore should not have been allowed in evidence at his trial.

The barrister said driving a boat under the influence of alcohol on the Thames in central London and speeding were both offences under bylaws of the Port of London Authority.

Charlotte Brown
Charlotte Brown (Metropolitan Police/PA)

He said police knew in advance that both Shepherd and Ms Brown had been drinking alcohol, and that he owned and was responsible for the boat, and therefore he should have been cautioned.

Mr Vullo said: “The only reason why he was not cautioned and given his rights to a solicitor on the day of the significant witness interview was due to a mistake by the police.

“What had happened is the investigation team had contacted the maritime police to ask whether offences had been committed … they were told no offences had been committed – including speeding and driving the boat with excess alcohol.”

He added: “There were clearly grounds to suspect Mr Shepherd of committing at least two bylaw offences.”

Mr Vullo said that not only was Shepherd not cautioned or offered a solicitor, but was “positively told” he was only going to be treated as a witness.

However, he told the court the interview “had the shape, the form and feel of an interrogation” and Shepherd was asked questions about offences.

Shepherd, wearing a green jumper and blue jeans, appeared in court over a video link from HMP Woodhill, where he is serving his sentence, and confirmed his name to court staff at the start of the case.

The appeal is being heard by Sir Brian Leveson and two other judges.

Ms Brown’s family did not speak to reporters as they entered the Royal Courts of Justice ahead of the hearing.

Shepherd, originally from Exeter, went on the run ahead of his Old Bailey trial and was convicted in his absence in July 2018.

He was later extradited to the UK from Georgia after handing himself in to police in the capital Tbilisi in January.

Jurors at Shepherd’s trial heard that he and Ms Brown, from Clacton-on-Sea, Essex, had been drinking champagne and went on a late-night jaunt in his boat past the Houses of Parliament.

Shepherd handed the controls to Ms Brown just before it overturned, tipping both of them into the cold water, the court was told.

He was plucked from the Thames alive, but Ms Brown was found unconscious and unresponsive.

Following his return from Georgia, Shepherd appeared at the Old Bailey in April and was sentenced to an additional six months for breaching bail.

He was jailed for a further four years at Exeter Crown Court last week after he admitted wounding with intent in relation to a drink-fuelled attack on a barman.

The court heard he struck former soldier David Beech with a vodka bottle on March 16 2018 after being asked to leave The White Hart Hotel in Newton Abbot, Devon.