THE makeshift wooden cross, bouquet of plastic flowers and waterlogged pink teddy bears that mark the murder scene scarcely hint at the brutality of the crime.

Jason Sweeney, a 16-year-old who planned to become a US Navy Seal, was lured to a swampy wasteland behind a post office depot in the Fishtown area of Philadelphia by his girlfriend — his first — with the promise of sex.

What he did not know was that the 15-year-old schoolgirl, Justina Morley, whom he had been dating for just two weeks, had apparently been plotting with his best friend and two other boys to rob him of his $500 (£300) wage packet and bludgeon him to death.

According to police, the assailants planned the attack for days and prepared for it that night by listening dozens of times to the Beatles’ Helter Skelter, the killer Charles Manson’s favourite song.

As Justina undressed, the boys struck from behind with a ferocity that left Jason begging for his life, raining down blows with a hammer, a hatchet and a brick until the hammer got lodged in his head.

One participant said that Jason’s last words were to Justina: “You set me up.” When he was dead, the four celebrated with a “group hug”.

“She was a pretty good girl,” Matt Ford, 13, said as he played by the cross this week. “I just think that they turned crazy over $500 to go and get high. That is what drugs do to you.”

The city, where the murder rate fell faster last year than any other in the US, was shocked as details emerged of the teenagers’ reported confessions. The Philadelphia Inquirer said: “It shakes a community to its soul to know adolescents in their midst could plot the brutal murder of someone they have known since childhood, just so they could get high. Depravity of this magnitude cannot be fully understood.”

Municipal Court Judge Seamus P. McCaffery, who viewed eight photographs of the body, told a remand hearing that the killing last month was “something out of the Dark Ages”.

A post-mortem examination showed that Jason suffered multiple blows. “The head was literally crushed. The only bone intact in his face was the left cheekbone,” Ian Hood, the coroner, testified. The injuries were so severe that the family held a closed-casket funeral.

“It’s horrifying,” said Brian Goodwin, 20, the Sweeneys’ neighbour, who went to school with one of the teenagers charged. “This is a tight neighbourhood. For something like this to happen, it’s shocking. Jason was a cool kid. Smart, too. He liked music.”

One of those said to have confessed is Jason’s best friend, Eddie Batzig Jr, who celebrated Jason’s sixteenth birthday at his grandparents’ home in Florida. Jason’s mother, Dawn, had told her son to end the friendship as she thought Eddie was leading him astray.

Also charged are Dominic Coia, 18, and his younger brother, Nicholas, 16. The three boys could face the death penalty; Justina is too young to be sentenced to death.

They are alleged to have split the $500 that Jason had got from working in his father’s building firm, and spent it on marijuana, heroin and the tranquiliser Xanax. “We took Sweeney’s wallet and split up the money, and we partied beyond redemption,” Dominic allegedly confessed.

Joshua Staab, 18, a friend of the accused, testified that the three boys could not find Justina and Jason and came to his house to call her mobile phone. When the four returned, they had bloody clothes, which he washed.

Mr Staab told the court: “She said she was happy she had a lot of money . . . she said it was a rush.”

Helter Skelter

Well do you, don’t you want me to make you
I’m coming down fast but don’t let me break you
Tell me tell me tell me the answer
You may be a lover but you ain’t no dancer
Look out helter skelter helter skelter
Helter skelter
Look out helter skelter

Explore World News

• World Agenda

• Iraq News

• US & Americas News

• Europe News

• Middle East News

• Asia News

• Africa News

• Ireland News

Times Recommends

• The Japanese Prime Minister is doomed: or is he?
• Brighton company 'involved in cyber attack'
• The art of survival: it’s all in the mind