Rio McFarlane was inadvertently caught in the crossfire of a petty dispute between rival gangs police said today as his killer was jailed for a minimum of 35 years.
The promising footballer was shot in the chest by Leon Pacquette in Peckham, south London in 2010.
"Rio was neither in a gang nor involved in criminality, but he inadvertently ended up in the crossfire of a petty dispute between rival gangs," Detective Constable Richard Williamson, Trident Gang Crime Command, said.
"For the sake of Rio's family, I am pleased that we have been able to bring the man responsible for his murder to justice and we hope today's verdict offers some comfort to them."
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The 52-year-old had previous convictions for violence but was not on the anti-terror watchlist.
In a statement Charlton Athletic said: Keith was a true hero who will be greatly missed by all the Charlton family and everyone at the club.