Beatrice Okechukwu remembers her sister Ruth as a real tomboy. No pink, God forbid, and no girlie things. “You could never get her in a dress. Not even for church on Sundays,” she says. Even more than dresses, Ruth hated the camera. So today, as Beatrice pays tribute to her 18-year-old sister who was stabbed to death in south London 17 months ago, there are almost no family photographs to share. Beatrice, 32, who works for a charity helping the homeless, can offer only memories.

Beatrice and her family, her father Ben, a pastor at a local Pentecostal church, her mother Pauline and her two brothers were at the Old Bailey last month to see justice done — and to come face to face with Ruth’s killer. Roberto Malasi, 18, pleaded guilty to two unrelated murders in the same neighbourhood.

The Angolan refugee was living in Peckham, south London, when he shot Zainab Kalokoh, 33, at a christening party. Two weeks later, in September 2005, he stabbed Ruth because she had shown “disrespect” towards him. He allegedly told friends that she had eavesdropped on a telephone conversation. Two days later he armed himself with a knife and, along with a gang of seven youths, lay in wait for her. Malasi, who was remanded in custody, will be sentenced this week.

Ruth was murdered in a quiet street on the outskirts of Peckham, an area that has dominated the headlines for the past week. Last Tuesday a 15-year-old boy, Michael Dosunmu, was shot when gunmen burst into his home. His was the third murder in four days in the area. Last Saturday Javorie Crighton, 21, on bail for drug offences, was stabbed to death. The following day a Nigerian man in his forties was shot dead; a man with him was wounded. The previous week James Smarrt-Ford, 16, was shot dead at Streatham ice rink, just a few miles away.

Since Ruth’s death her family have appealed to their local community to help to stamp out the violent culture that is rife on the streets of Britain. “I feel shocked and saddened by what has happened,” Beatrice says of the recent murders. “And for the first time I am beginning to feel afraid in my neighbourhood.”

To help to combat the problem, she wants to see the introduction of after-school clubs in secondary schools to help to keep children occupied and off the streets. “But parents have to play their part, too,” she says. “It can’t just be up to teachers. Mothers and fathers need to know where their children are, what they are doing and who they are with.”

And it’s not just a Peckham problem. “I think what happened to Ruth could have happened anywhere in Britain, in any city, any town and any street,” she adds.

The statistics prove her point. Figures from the Home Office reveal that the number of deaths from sharp instruments such as knives between 1998 and 1999 stood at 202. But by 2003 that number had increased by more than 25% to 268.

What is happening on the streets of Peckham? Is it worse than any other deprived area? Camilla Batmangheldijh, who runs Kids Company, a charity for disadvantaged children, says the trafficking of firearms in that area is the only factor that distinguishes it from the rest of Britain. “These murders stem from a street economy that revolves around the drug trade and other criminal activity,” she says. “The savage aspects of the human being are having to be deployed in order to survive.”

For Batmangheldijh these young gang members are not feral children but “forgotten” ones who have been failed by their families and are often disturbed. They may have absent fathers or have parents who are drug addicts or who are mentally ill: “Their basic needs of love, food and shelter are not being met. They really do have nowhere to go.”

When that happens, she adds, society in the form of youth workers and mentors must act in loco parentis. She is also calling for the introduction of centres across the country, run by trained staff and youth workers, where they can drop in: “They need human relationships which are so lacking in their lives.”

Ruth was the youngest of four children born to Ben and Pauline after they left their native Nigeria in the early 1970s. They settled in an estate off the Old Kent Road, southeast London. With a 13-year age gap between them, Beatrice felt more like a second mother to Ruth than a sister: “When I left home she was still a child. But we were close in that we would always talk about her life and her plans.” During one of their last conversations, she encouraged her sister, who was still living at home, to aim for university. Ruth, studying for a BTEC at a west London college, talked of reading sports science at Cambridge or Brunel.

The family has been piecing together what happened to Ruth in the days leading up to her death. On Friday, September 9, she had gone to visit a female friend at her house. The girl took a call on her mobile phone from a boy the family now knows to have been Malasi. He was abusive to her. Ruth was incensed and seized the phone and began arguing with him.

On Saturday evening she went to a birthday party attended by Malasi. He bumped into her and she “nudged” him. According to various accounts heard by the family, he planned to kill her there, but she was surrounded by friends.

On Sunday, the last day of Ruth’s life, her parents went to church. That afternoon she walked round the corner to a girlfriend’s house. What happened next is unclear, but it seems that they arranged to meet a boy later on. The pair walked to a quiet road where Malasi was sitting in a car waiting for them.

Ruth got in beside the boy she was meeting, whereupon a gang of seven youths plus Malasi came from nowhere. She was stabbed in the chest by Malasi as she sat in the car. She managed to get out and reach for her mobile phone and was in the middle of calling for help when she slumped on the pavement. Passers-by called an ambulance.

She was pronounced dead shortly after her arrival at nearby King’s College hospital. In denial, Beatrice asked to see Ruth’s body. Cuts to her hand and face showed that she had put up a fight. “Her eyes and mouth were open. She looked in shock.” It is a cruel image to have to carry around. Beatrice believes that Ruth was lured to her death and that she was simply too trusting. “She was streetwise but not streetwise enough,” she says.

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