A three-year investigation into the murder of John Lennon has unearthed a series of extraordinary inconsistencies – including the suggestion that detectives may have fundamentally misunderstood how the shooting happened.

British author and TV producer David Whelan has exhaustively examined Lennon’s fatal shooting on December 8, 1980, as he and his wife Yoko Ono returned to their home in the Dakota Building overlooking New York’s Central Park.

Whelan has unearthed a trove of documents relating to the killing, including gunman Mark Chapman’s ‘hit list’ – published for the first time here – which as well as the former Beatle also featured Marlon Brando and former First Lady Jackie Kennedy Onassis.

The prosecution’s version of events, accepted by the courts, was that disturbed loner Chapman lay in wait for Lennon and shot five times, four of the bullets hitting his victim in the back. But this now appears to be riddled with contradictions.

Instead Whelan’s witnesses suggest that the way the shooting was officially recorded may have been completely wrong – with the fatal shots fired into Lennon’s chest rather than back.

The surgeon who treated Lennon and the two nurses who assisted are all adamant that Lennon was shot in the front, with the four bullets grouped closely together, suggesting a high degree of marksmanship, and three passing straight through his body and out of his rear shoulder.

Other evidence gleaned by Whelan about those who may have influenced Chapman has led him to question whether the young man might even have been ‘groomed’ for the assassination through manipulation or even hypnosis by powerful backers with links to right-wing Southern Christians, the US military or the CIA.

Mr Whelan alleges that key information surrounding the murder was ‘hushed up’ by the NYPD and the District Attorney’s office, including 122 unidentified pills found in Chapman’s hotel room, which were supposedly sent off to a lab for drugs analysis. The results have never been revealed.

The various items found by the police which were made public are listed on a typed docket, including an expired passport, a pocket bible and a Wizard of Oz placemat. Whether Chapman’s death list was found in the hotel room isn’t clear, but it is not listed on the docket.

Having obtained Detective Hoffman’s original notebook and other documents associated with the case, Mr Whelan pointed out that no single eyewitness, including Yoko Ono, saw Lennon being shot by Chapman.

Ono’s exact location when John was shot, has changed several times, via various witness statements she gave around the time of her husband’s murder, understandably, no doubt, given her emotional turmoil.

Much more information surrounding Chapman and the murder would no doubt have emerged – and the evidence tested – in court, but no trial ever took place – and that in itself is suspicious, according to Mr Whelan.