A gang defendant has died after being shot as he tried to attack a witness testifying against him in a court in the US state of Utah.
Siale Angilau, 25, died in hospital in Salt Lake City after being shot in the chest as he rushed the witness stand with a pen in an "aggressive, threatening manner", the FBI said.
Angilau was one of 17 people named in a 29-count racketeering indictment filed in 2010, accusing gang members of assault, conspiracy, robbery and weapons offences.
Under standard procedures, Angilau was not restrained in the courtroom, the FBI said.
A mistrial was declared after the shooting. Perry Cardwell, who was in court, said Angilau was shot several times as he lunged towards the stand. The witness, who was unhurt, was testifying about gang initiation.
"It was kind of traumatising," said Sara Jacobson, Cardwell's daughter, of the shooting.
Prosecutors said Angilau robbed five convenience stores and assaulted clerks in Salt Lake City from 2002 to 2007. A clerk was shot in the final robbery.
He was accused of assaulting a federal officer with a weapon and discharging a firearm during a crime in 2007.
Angilau had been in Utah state prison since September 2007. He was arrested in August 2007 for a probation violation and pleaded guilty a year later to obstruction of justice and failure to respond to a command of a police officer.
The trial was among the first at the new US$185 million federal court block opened just one week ago in downtown Salt Lake City. The towering building is designed to withstand blasts and also contains bulletproof glass in some areas.
The security measures include separate routes in and out for judges, prisoners and the public.
The court was temporarily closed after the shooting.