A former police firearms instructor "executed" his daughter's partner in a "blind rage", a jury has been told.

David Hucker, 69, blasted Robert Williamson twice with a 12-bore shotgun after the pair argued at his home in Dartford Road, Dartford, in May.

In his concluding remarks at Maidstone Crown Court prosecutor Nicholas Corsellis QC said: "In a blind rage he shot him first in the chest and, knowing he was mortally wounded, shot him in the neck from above in a most ferocious and cold hearted way.

"That second shot amounted to an execution."

He said remarks made by Hucker and heard by the 999 operator Mr Williamson had phoned as he "cowered" in the bedroom were "a most compelling confession": "I'll boot that door down," "I ******* warned ya," and finally "**** you".

But Oliver Saxby QC, defending, said 43-year-old Mr Williamson "was in full on taunt mode" after he arrived at Hucker's home for a second time after the pair had rowed.

Mr Williamson had a cocaine habit which was costing £1,000 a week by the time of his death and due to financial difficulties he and Hucker's daughter, Samantha, were moving in.

Mr Williamson arrived at 9am on May 11 with a box of belongings but soon left after an argument which started when he got himself entangled in a fly screen.

He returned with something that "looked like talcum powder" smeared beside his nose and at first appeared "conciliatory" but Hucker told him to leave and tensions boiled over.

Mr Williamson threatened to kick Hucker out of his own home and walked upstairs laughing and saying "no wonder she left you", in reference to Hucker's ex wife.

Experienced shooter Hucker pursued him with a competition shotgun intending "to frighten him" and "shoot the ceiling" but instead blasted Mr Williamson twice.

Mr Corsellis told the court Mr Williamson was "under attack by a man who was acting like a lunatic" and that it couldn't be discounted that Hucker had armed himself "in preparation" before the encounter.

He said the "rain of blood" which followed the second shot showed Hucker could not have been unaware Mr Williamson had been hit, as he claims.

"Robert Williamson had got too mouthy. He still had, in David Hucker's words, 'all that old gob'," he said.

But Mr Saxby said Hucker's "mind was all over the place", that Mr Williamson after being told to leave again instead was "staying and provoking and goading and befuddling Mr Hucker".

Telling him he'd sell his house and calling him a "pathetic old man" had "discombobulated" Hucker to such an extent that he was not acting rationally and could therefore not form an intention to murder Mt Williamson, he argued.

"David Hucker would have worried Robert Williamson would engineer a situation where he was kicked out," he said.

Mr Williamson's taunts caused Hucker in his words to "go off like Mount Vesuvius" and "lose it".

The court previously heard how Hucker, of previous good character, and Mr Williamson were "like father and son" and both members of the same Masonic lodge.

Ms Hucker said they were both "alpha males" and described how her partner Mr Williamson "was a little bit of a Jekyll and Hyde character," becoming violent after using cocaine.

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The 999 call made by Mr Williamson was played the jury. A loud crack followed by Mr Williamson saying "He's just shot me in the ******* chest!" could be heard.

Hucker could be heard saying "I ******* warned ya" before a second crack and a thud which sounded like a body slumping to the floor.

Hucker then picked up another telephone, claiming he didn't realise Mr Williamson had already dialled 999, and told the operator: "I've just shot him... I was sensible 'til about five, 10 minutes ago."

He told the jury he had intended for both shots, the first which hit Mr Williamson's chest and the second his head, to hit the ceiling.

He told prosecutor Nicholas Corsellis QC previous comments made to neighbour Barry Palmer that Mr Williamson's "gobby" attitude was "nothing a shotgun couldn't fix" were made "jokingly for banter".

When police arrived Hucker said: "I used to be a firearms instructor for 40 years and what did I do, shoot the ****** son-in-law?"

Hucker has no previous convictions and trained Met, Kent and City of London armed police officers for more than 30 years.

He would go shooting "sometimes up to seven days a week" and previously worked at JJ's Clay Shooting Club in Darenth Woods, near Bean.

Hucker denies murder. The jury retired to consider the verdict yesterday afternoon.