A father and son were shot dead in an execution-style murder moments after party guests left their home in a quiet neighborhood.

Nicholas Pence, 25, and his father David, an oil company manager, had been celebrating a victorious football game in their garage in New Orleans, Louisiana, on Wednesday.

But moments after jovially waving goodbye to the last-remaining revelers shortly before midnight, they were both shot dead at close range in an attack that shocked and baffled the quiet community of Metairie.

They were found by David's wife, Nicholas's mother, who had been in a bedroom when she heard gun shots.

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Shocking: Nicholas Pence, 25, (left) and his father David, 56, (right) were shot dead 'execution-style' at home on Wednesday night after a football party in their garage, or 'man cave'. Police believe it was a botched burglary

Tragic: They were found lifeless by Elizabeth Pence (center), mother to Nicholas (second left) and wife to David (right) moments after the shooting, which has left the quiet neighborhood of Metairie in mourning and shock

Charged: Police arrested Dexter Allen, 17, (left), and Haraqyon Degruy, 18, (right) in connection with the killings

On Sunday, police revealed 18-year-old Haraqyon Degruy and her friend Dexter Allen, 17, have been charged with the double killing.

Neither have a 'significant' criminal history, officers revealed.

The police investigation has failed to determine at link between the alleged assailants and their victims, or a motive.

David Pence, a manager at a New Orleans branch of the international oil firm Baker Hughes Inc, was shot three times in the chest while sat in an armchair.

Nicholas was shot in the face and back. He was found lying on the floor of their so-called 'man cave'.

Elizabeth Pence dialed 911 to report the shooting, and the theft of her purse, iPod and iPhone.

Friends of Nicholas, known to friends as Nick or 'Peezy', have set up a fundraising page to supplement funeral costs and support his surviving mother and sister.

The family lived on Clifford Drive, a leafy part of Metairie, which is one of New Orleans' wealthier areas

Initial reports suggest it could have been a botched armed burglary, as Allen and Degruy were linked to earlier car break-ins.

Addressing a press conference on Sunday, Jefferson Parish Sheriff Newell Normand said: 'Once again, this particular happenstance was completely, totally, shock-the-conscience type of homicide — obviously execution-style, very close.'

Members of the community have expressed their horror, describing Nicholas and David as outgoing and lively neighbors.

'They were very good people. They got along with everybody.' close family friend Paul Meyer told WWL TV.

'I can't comprehend how someone could do this to a family like that.'

Another friend said he was in the garage with Nicholas just minutes before the murder.

Police believe 17-year-old Allen fired the fatal shots before running to the car and saying 'I just shot two people' to Degruy, who allegedly drove off, the New Orleans Advocate reported.

Degruy has been charged with two counts of being an accessory to first-degree murder and one count of vehicle burglary.

Allen is being held on charges of fleeing police and two counts of first-degree murder.

Weapon: Col John Fortunato of the Jefferson Parish Sheriff's Office holds the heavy-duty gun which authorities believe was used to kill David, an oil company manager, and his son Nicholas after their party this week

A police report says the younger Pence had pointed out a suspicious white Toyota crawling through the street

Neighbor and friend Michael Soignet has described the agonizing moment Mrs Pence returned to the address, saying: 'She just gave me a strapping hug, and I choked up. She choked up. There were just no words.'

Describing the victims to The New Orleans Advocate, she said: 'You'll never find anybody that's going to throw out a bad word on them, and if somebody does, they don't have their story right.