Siale Angilau, 25, died at a hospital after he was shot in the chest as he rushed the witness with a pen in an “aggressive, threatening manner,” the FBI said in a news release.
Angilau was shot several times in front of a jury that had been selected on Friday.
Angilau was one of 17 people named in a 29-count racketeering indictment filed in 2010 accusing “Tongan Crip” gang members of assault, conspiracy, robbery and weapons offenses.
Under standard procedures, Angilau was not restrained in the courtroom, the FBI said.
Perry Cardwell, who was in the courtroom with his adult daughter, said Angilau was shot several times as he lunged toward the witness stand.
At least six shots were fired, he said.
The witness, who was not injured, appeared to be in his mid-20s and was testifying about gang initiation, Cardwell said. The person was not identified.
Cardwell and his daughter were in court to support his mother, Sandra Keyser, who was punched in the face during a holdup in 2002 and was scheduled to testify.
“It was kind of traumatizing,” Sara Jacobson, Cardwell’s daughter, said of the shooting.
Angilau was accused of assault on a federal officer with a weapon and discharging a firearm during a crime of violence on Aug. 11, 2007.
Angilau was the last defendant in the case to stand trial, U.S. attorney’s office spokeswoman Melodie Rydalch said.
A mistrial was declared after the shooting. In her order, U.S. District Judge Tena Campbell said members of the jury were visibly shaken and upset.
Angilau’s attorney, Michael Langford, declined to take questions as he left the courthouse.