Six young men who gang raped, tortured and murdered a teenage schoolgirl and shot her friend in the head were yesterday jailed for life, with recommended minimum terms of 23 to 27 years.

Mr Justice Penry-Davey told the men in Reading crown court they had been involved in a "brutal and merciless execution" of 16-year-old Mary Ann Leneghan in a Reading park. The girls had been used as bait, he said, and subjected to "gratuitous torture" and "gross sexual abuse".

He recommended that one of the killers, an 18-year-old Kosovan illegal immigrant, should be deported after he had served his sentence.

Mr Justice Penry-Davey said Adrian Thomas, 20, of south London, a drug dealer who moved to Reading to carve out a new territory, was the "prime mover" in the attack. Thomas, Michael Johnson, 19, and brothers Joshua Morally, 23, and Jamaile, 22, all from south London, were given life sentences with the recommendation they serve 27 years in prison.

It was Thomas, who rented a flat above a massage parlour, who had gathered the group from south London to kidnap Mary Ann and her friend last May.

He blamed the girls for setting him up for a robbery. The girls were taken to the Abbey House Hotel in Reading, where they were subjected to gang rape, drugged and tortured before being driven to Prospect Park in the west of the town, where Mary Ann was stabbed more than 40 times. Her friend witnessed the attack before being shot in the head, but she survived to give evidence against the gang.

As Thomas was led to the cells yesterday his father, Tony Thomas, disowned him. "I would love to curl up and forget Adrian is my son. Adrian is past caring about anyone but himself," said Mr Thomas. "Adrian has a vengeful, petulant side. He has shown no remorse."

The judge jailed the killers after hearing that Thomas and three others were meant to be under the supervision of the probation service in London when they murdered Mary Ann.

The 18-year-old girl who survived the attack told the court it was Johnson who had repeatedly stabbed her friend in the neck, chest and stomach with a flick knife.

The judge said Jamaile Morally, 22, had put a gun in Mary Ann's mouth and shot her friend in the head as she knelt in the park having just witnessed the murder.

His brother Joshua had been responsible for "gratuitous violence" and was a prominent member of the gang, the judge said.

Llewellyn Adams, 24, whose family are standing by him, was given life with a recommendation he serve 23 years. He drove the Nissan Primera used to carry the girls.

Indrit Krasniqi, 18, should serve 23 years, the judge said. He confessed to stubbing out cigarettes on the girls' skin and pricking them with a knife.

Krasniqi, who arrived in Britain aged 13 as an illegal immigrant from Kosovo, was due to have been deported two weeks before the murder - when he turned 18.

He had received a community punishment order in January 2005. Thomas, Johnson and Jamaile Morally were also under probation service supervision.