December was always the best of months for Vincent Romero’s young son: first Christmas; then his birthday, four days later. Yet when he turns nine later this month, he will be awaiting trial in an Arizona court on charges of double murder.

The disturbing case of an eight-year-old boy who is alleged to have shot his father and another man last month has stunned the small desert town of St Johns, 170 miles northeast of Phoenix.

It has also raised awkward questions about America’s treatment of juveniles charged with serious crimes. The Romero boy, whose full name has not been released, made a video-taped confession to police, but the validity of his statement is being challenged by defence lawyers, who have complained that no adult family member or lawyer was present when he was questioned.

The case has produced a Christmas headache for Judge Michael Roca of Apache County, who has issued a gagging order on all parties, pending a psychiatric evaluation of the boy this week.

Roca must decide whether the child should be allowed to leave a local juvenile detention centre to spend Christmas and his birthday with his mother, Eryn Bloomfield. When he was allowed home for two days at Thanksgiving, relatives of Timothy Romans, the other man he is alleged to have killed, were furious that he had been freed before undergoing psychiatric tests.

Bloomfield and Romero were divorced, and the boy was living in St Johns with his 29-year-old father and a stepmother, Tiffany. Romans, 39, was renting a room in their house.

Exactly what happened on the day of the shooting remains unclear, but prosecutors have claimed that the boy was spanked so regularly by his father and stepmother that he had begun writing a log of assaults.

He told one child welfare officer that his 1,000th smack would “be my last”.

Romero senior was a well-liked construction worker in St Johns, which has a population of 4,000 and calls itself the “Town of Friendly Neighbours”. He was awarded custody of his son after his 2001 divorce.

“This child seemed okay with the world,” said Connie Grugel, who lives on the same street as the Romeros. “He was a happy little guy, the kind you’d want to hug.”

Several neighbours reported hearing popping noises from the Romero home at about 5pm on November 5, shortly after the boy climbed off a school bus. Romero’s body was discovered on the stairs and Romans’s was found outside.

Both men had been killed with four or five shots from a .22 rifle that needed to be reloaded after each shot.

Police said later the rifle belonged to the boy, who had been taught how to shoot by his father. In a rambling statement to police, the boy at first suggested that someone else had shot the two men and that he had then finished off his father “because he was suffering, I think”.

A local police officer testified that the boy was “mad at his dad” because the previous evening his father had ordered Tiffany to smack him five times after he forgot to bring some papers home from school.

The case has put prosecution lawyers in a quandary: while they acknowledge that an eight-year-old should not be treated like an adult, the alleged element of premeditation is difficult for them to ignore.

A spokesman for the Romans family said he doubted justice could ever be served. “No matter what you do – keep him in, let him go – it’s a no-win situation,” the spokesman added.

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