Darcy Austin Bruce, 20, from Fulham, was gunned down outside Wandsworth Prison, south-west London, on Friday afternoon.

Darcy Austin Bruce, 20, from Fulham, was gunned down outside Wandsworth Prison, south-west London, on Friday afternoon.A post-mortem examination gave the cause of death as multiple gunshot wounds to the torso.It is believed he was visiting the prison when he was killed. Police said they are keeping an open mind as to the motive.Three men aged 19, 22 and 26 were arrested on suspicion of being involved in the murder, a Metropolitan Police spokeswoman said. Two men wearing crash helmets were seen running away from the scene after a series of gunshots were heard.Mr Bruce was pronounced dead at the scene on Heathfield Road.Officers from Operation Trident, which investigates gun crime in the black communities, are investigating.Reports said that at least four shots were fired at about 2.30pm.One eyewitness said two men wearing motorcycle helmets with dark visors covering their faces were acting suspiciously nearby before the shooting. The woman, who asked not to be named, said the two men appeared to be waiting in the street outside the prison entrance.She said: "I saw two men in the street. They made me nervous. They were wearing motorcycle helmets with the fronts pulled down over their faces. They were apart from each other in the street right outside the entrance. One was sitting on a wall. That is when I heard several bangs. I thought they were gunshots. There were at least four. One of the staff members said there had been a shooting."