Doreen Lawrence and Prime Minister David Cameron (Photo: UPI/Hugo Philpott /LANDOV)

Flanked by supporters, Doreen Lawrence, the mother of slain teen Stephen Lawrence, marked the 20th anniversary of her son’s tragic death in a somber memorial service attended by British Prime Minister David Cameron.

Stephen was killed April 22, 1993, after he was attacked by group of white teens. Since his death, Lawrence’s mother has campaigned publicly to have her son’s killers brought to justice and remains an active voice in U.K. racial activism.

“I believe that Stephen’s life had value. His life is giving life to other young children,” Doreen Lawrence said Monday according to the Evening Standard.

In addition to the prime minister, the service was also notably attended by Opposition leader Ed Miliband and London’s Metropolitan Police commissioner Sir Bernard Hogan-Howe.

After the initial investigation into Stephen’s death was found to be mishandled due to incompetence and institutional racism within the police force, Britain enforced sweeping race relations legislation that contained some of the toughest anti-discrimination laws in Europe.

Even with the sizeable gains achieved since the teen’s death, many say there is still much work to be done.

"While there has been progress in the 20 years since Stephen's death, not enough has changed," Symon Sentain, chair of the Stephen Lawrence Charitable Trust, told the Standard.

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