A convicted murderer was found guilty on Monday of gunning down a retired army officer in cold blood.
Christopher Docherty-Puncheon, 33, shot Lieutenant Colonel Robert "Riley" Workman, 83, on his doorstep in Furneux Pelham, Hertfordshire, in an "execution-style" killing in 2004.
Docherty-Puncheon, from nearby Stocking Pelham, denied murdering his former employer Lt Col Workman but jurors at St Albans Crown Court found him guilty following a four-week trial.
Retired army officer was gunned down on his doorstep
The defendant, dressed in a dark suit and striped tie, remained expressionless as the verdict was read out after the jury of six men and six women deliberated for 17 hours and 31 minutes.
Docherty-Puncheon confessed to killing Lt Col Workman to two cellmates while he was on remand over a separate murder charge, describing himself to one of them as a "modern-day hitman" who killed people for money.
He had worked as a pest controller for Lt Col Workman, known by many as "The Colonel", and the court heard the pair also had a sexual relationship.
On the evening of January 7 2004, he rang Lt Col Workman's doorbell and then retreated before shooting him with a sawn-off shotgun from between 11 and 13 feet away.
The colonel was found on the doorstep of his home, Cock House, Causeway, by his part-time carer Josette Swanson the next morning.
She found him with his feet hanging out of the doorway of the cottage, and thought he had suffered a heart attack as she did not notice the shotgun wound to his chest.
Docherty-Puncheon is already serving a life sentence for the murder of Fred Moss, 21, in late 2004.
Moss was described as being killed in an "execution-type" manner, with Docherty-Puncheon shooting him in the head, then cutting up his body and burning it in an incinerator.
It was while on remand awaiting trial for that murder that he boasted to his cellmate of killing the colonel and also of committing another murder in Australia in exchange for money.
He said he bought a top-of-the-range Range Rover with the proceeds.
Docherty-Puncheon later claimed he bought the vehicle with money earned from killing Lt Col Workman, telling the cellmate he had known the colonel since 1998 and had helped him with a wasp nest on his rural property.
The trial heard that Docherty-Puncheon went on to speak of his relationship with widower Lt Col Workman in detail, describing the older man as wealthy and generous with money.
Convicted killer Christopher Docherty-Puncheon has been found guilty of murdering a retired army officer
He told the cellmate, who cannot be named for legal reasons, that he killed the colonel in connection with a matter that had occurred seven years earlier, later saying that he had been paid to kill him.
When that cellmate told police what he had heard, he was moved to a different prison.
But Docherty-Puncheon's new cellmate, John Horn, also claimed the defendant confessed to him, this time with a different motive that involved Mr Moss.
Docherty-Puncheon, who was convicted of Mr Moss's murder in 2006, claimed his cellmates made the confessions up.
He also told the court that claims that he had a sexual relationship with the colonel were made up and a product of village gossip, like something out of TV detective drama Midsomer Murders.
Justice John Saunders sentenced Docherty-Puncheon to life imprisonment, with a minimum jail term of 32 years before he can be considered for bail.
He said: "Colonel Workman was 83 when he was shot down.
"He was unarmed and in poor health. He had neither the capacity nor the opportunity to defend himself.
"He was living out a peaceful retirement in a cottage in a small village in rural Hertfordshire when his life was brutally cut short.
"It was a terrible crime and people living in that rural community were shocked by the gunning down in cold blood of one of their elderly neighbours.
"Such an event is bound to create feelings of fear among residents which can continue for a long time.
"I cannot say for certain what the reason for the attack was. Several have been suggested during the evidence but none have been proved to my satisfaction. Maybe we will never know."
Justice Saunders said he was satisfied the colonel's murder and the death of Mr Moss were connected.