John 'Goldfinger' Palmer 'killed by professional gunman'
The shooting of a notorious criminal "bears all the hallmarks of a professional hit", police have said.
John "Goldfinger" Palmer, 65, who allegedly amassed a fortune in a time-share scam, was shot six times in the chest at his South Weald home in June.
Essex Police said they believed his killer climbed over a fence and shot him from an area not covered by CCTV.
There was "speculation" Palmer was linked to other organised crime such as the Hatton Garden raid, they added.
Det Ch Insp Stephen Jennings said: "Due to John's significant criminal history there are people or groups of people who may have wished to do him harm.
"Therefore our search is not just for the gunman but for a person or group of people who may have commissioned the killing."
Palmer was due to stand trial and police believe his death could relate to concerns about what he would say in evidence during court proceedings.
A life of crime
- Born near Birmingham, his nickname derives from his connection to the 1983 £25m Brink's-Mat gold bullion robbery. He was acquitted but his associate Kenneth Noye was convicted
- Palmer was jailed for eight years in 2001 for a £20m timeshare fraud involving 16,000 victims. He served half his sentence and a confiscation order for £33m was overturned at the Court of Appeal
- In 2005, he was declared bankrupt with debts of £3.9m, despite a reputed wealth of £300m
- Two years later, he was arrested by Spanish police and charged with fraud, firearm possession and money laundering
- He was due to stand trial on these charges at the time of his death
Det Ch Insp Jennings said: "There are two very significant main lines of inquiry at the moment, the first being that John was due to stand trial in mainland Spain relating to real estate fraud that followed an eight-year investigation.
"The second is a combination of factors throughout 2015 which included a number of significant crimes in the UK, significant law enforcement intervention into organised crime in the UK and significant arrests of people in organised crime groups."
Speaking ahead of a BBC Crimewatch appeal, police said the crime scene had been "professionally" stripped of evidence.
No shots were heard in the house and his body lay undiscovered until it was found by his son's girlfriend an hour later.
Palmer had recently had surgery and it was initially thought he had suffered a cardiac arrest.
It is thought that this surgery was common knowledge among friends and family and could have been deliberately used to disguise the injuries.
A week later, a post-mortem examination found the convicted conman had been shot in the chest six times, which prompted an investigation by the police watchdog.
Detectives found a hole in the fence surrounding Mr Palmer's sprawling grounds which they believe the gunman used to watch his movements.
"We believe the killer entered the garden over the fence, close to where he was, and made his way to where Mr Palmer was burning the rubbish before shooting him," said Essex Police.
"We do not know at this time whether a silencer was used or not but no modifications had been made to the bullets.
"The murder bears all the hallmarks of a professional hit."
The force refused to comment on whether Palmer was a police informant at the time of his death.
Police said they want to trace two or three men seen digging in woodland close to Palmer's home the day before the murder, late in the morning.
One was aged 30 to 40, just under 6ft (1.8m) and of average build with dark hair.
A man was also seen in Weald Country Park, next to Palmer's home, on the day he was shot.
He was white, in his early 20s, about 5ft 10in (1.78m), slim, with short and dark-blond hair. He was wearing light blue jeans and a light-coloured baggy sweat top.
Last year, a 43-year-old man arrested on suspicion of conspiracy to commit murder was released without charge.
Mr Palmer's partner, Christina Ketley, said he had turned his life round prior to his death.
She said: "He had made mistakes in his life, but he had paid for those mistakes.
"I was incredibly proud of the way he had readjusted to a very, very normal life."
Crimewatch is on BBC 1 on Thursday 10 March at 21:00 GMT and available on the BBC iPlayer after broadcast.