The case of an adoptive Russian teen arrested in connection with the murder of his American parents has taken an unexpected turn after court documents revealed that he was starved and tortured by them.

The documents stated that Carl Edward Brewer was made to sleep on a concrete garage floor and deprived of food when he got in trouble at home. He was brutally disciplined by his adoptive parents, which might have forced him to take the extreme step. Several of Brewer's teachers have testified about the brutal accounts that the boy had suffered, the Daily Mail reported.

The 18-year-old is accused of killing 60-year-old American Airlines pilot Troy Gene Brewer and his wife Mary Brewer, 64, in their house in Crowley, Texas, in November 2016 over "family disturbance gone wrong".

He was arrested on 30 November after a night-long standoff with a Special Weapons and Tactics (SWAT) team.

His father's body was found in a bathroom, while the mother's body was in a den of their home in the 800 block of Buffalo Court in Crowley. The Tarrant County medical examiner's office has said that the pair died due to multiple gun shots, the Star Telegram reported.

But the young man's attorney Jack Strickland insisted that the case has two sides and one side says that the boy's parents were brutal disciplinarians.

A number of teachers from Deer Creek Elementary School in Crowley, where the teen studied, said that he was "very intelligent" and that he gave them "very little trouble". One educator told investigators that he was starved as a punishment by his parents, while another mentioned how he was forced to sleep on concrete floor.

One teacher even described the Brewers as "very military" but not very loving, while another told investigators that the teen was "so starved for attention" that when she gave him a hug he "just melted", the court documents stated.

Teachers also said that they informed officials with Child Protective Services (CPS) about the alleged cruel behaviour of the parents but a CPS spokeswoman Marissa Gonzales said in an email dated Thursday, 4 January, that they were not involved in the investigation into the parents. "Any involvement with the family before that is confidential," Gonzales added.

Crowley police had arrived at the crime scene in November 2016 after they received an anonymous call from a friend of Brewer, who was smoking marijuana with him at the time when the teen told him about the murders.

Officers went to the scene and recovered the bodies. Brewer was the only child living with the old couple, his two biological brothers – all adopted by the pair – were living out of the state.

Brewer has been charged with two counts of murder and remains in the Tarrant County Jail in lieu of $500,000 (£368,475) bail.