They believe the gunman or one of his accomplices was wearing distinctive Nike shoes, with two of their trademark swoosh signs removed, when Brendon Lawrence was shot.

The schoolboy was shot three times after he stepped out of a car in the St Ann's area of Nottingham on 19 February last year.

Several people have been questioned in connection with the shooting, but no one has been charged.

Brendon Lawrence was shot three times

Police said the inquiry team hoped to trace a man who was wearing a pair of black Nike Bohemian shoes at the time of the murder.

Detective Chief Inspector Helen Jebb said: "We believe that these were very distinctive shoes, which were only available in J & D Sports stores.

"Between their distribution and the time of the murder, only 16 pairs were sold in Nottingham.

"The trainers had swoosh symbols on both sides of the shoe, but on the outside of each trainer the symbol had been unpicked and removed."

Protest march

She said officers discovered the shoes with a blue and green jacket in a Ford Fiesta XR2 stolen from a friend of Brendon's at the scene and dumped in nearby Westville Gardens.

Two black men had been seen driving the car, registration number G303 NWG, but despite extensive investigations the pair have not been traced.

On Saturday Brendon's mother Janice Collins led a march of 2,000 people through Nottingham to demand tighter gun laws.

The group, Mothers Against Guns, organised the rally and a public meeting attended by Home Office Minister Lord Falconer to call for mandatory 10-year sentences without parole for those caught carrying firearms.