SALT LAKE CITY » When Utah’s new federal courthouse opened last week, it came with security improvements that are becoming standard around the country: separate entrances and elevators for judges, defendants and the public; bullet-resistant glass and paneling; and vehicle barricades to keep car bombs at bay.

Even the design of the courtrooms, with plenty of sunlight and space, can help calm witnesses or defendants in high-stress cases, some judges believe.

But nothing can prevent every violent courtroom outburst. Authorities said that when a 5-foot-11, 230-pound, pen-wielding defendant rushed a witness during his racketeering trial Monday, a more old-fashioned form of security left him dead: an armed U.S. marshal.

Siale Angilau, 25, was shot several times in front of stunned jurors, lawyers and courtroom watchers. He was one of 17 people named in a 2010 indictment accusing "Tongan Crip" gang members of assault, conspiracy, robbery and weapons offenses.

The unidentified witness, who was unhurt, had been testifying about gang initiation when Angilau charged him, said Perry Cardwell, who was in the courtroom. Cardwell was there to support his mother, Sandra Keyser, who was punched in the face during a holdup in 2002.

Shootings at federal courthouses are rare, though not unheard of, around the country.

Last year, a former police officer who told friends he was dying of cancer was killed by law enforcement after he sprayed bullets into a federal courthouse in West Virginia. In 2012, a man committed suicide at a federal courthouse in Alabama, and in 2010, a man started shooting in the lobby of the Las Vegas federal courthouse, killing a court security officer and wounding a deputy U.S. marshal. The gunman was killed in a shootout.

Shootings in courtrooms themselves are even less common, largely because metal detectors ensure armed spectators don’t reach them.

But defendants usually are not shackled when they appear at trial, absent extraordinary circumstances, making their outbursts unpredictable. Courts have held that it’s unfair to defendants for jurors to see them restrained. It’s unclear whether the U.S. Marshals Service, which provides security for judges and federal courthouses, had any unusual concerns about security in Angilau’s case.

Prosecutors say Angilau, also known by his street name "C-Down," was a member of the Tongan Crips, a group of men of mostly Tongan descent that are aligned with a larger Crip culture in the Western United States. They have rivalries with "Blood" gangs and a gang of ex-members known as the "Tongan Crip Regulators," court records show.

The last defendant in the case to stand trial, Angilau was accused of robbing convenience stores and assaulting clerks in Salt Lake City on five occasions from 2002 to 2007. A clerk was shot in the final robbery. He was also accused of assaulting a federal officer with a weapon on Aug. 11, 2007.

Angilau’s trial was among the first at the new $185 million federal courthouse in downtown Salt Lake City, next door to the century-old federal facility it replaced.

U.S. District Judge Tena Campbell declared a mistrial after the shooting, noting in her order that jurors were visibly shaken and upset. She issued a separate order extending the jurors’ term of service "until counseling is no longer needed."

Angilau’s attorney, Michael Langford, declined to take questions as he left the courthouse.

Angilau 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, court records show. He remained in Utah state prison until he was handed over to U.S. marshals on Friday, said Utah Department of Corrections spokeswoman Brooke Adams.

Marsha Pechman, the chief U.S. district judge in Seattle, noted that although state courts handle many of the most emotionally charged cases, including family-law matters, security is never far from the minds of federal judges.

In 2005, six weeks after Seattle’s federal courthouse opened, Seattle police shot and killed a man who walked into the lobby with an inert grenade.

That same year, a delusional man angry over the dismissal of his medical malpractice case shot and killed the mother and husband of Chicago U.S. District Judge Joan Lefkow at the judge’s home.

Pechman said she believes the stately, quiet, light and spacious feel of newer federal courthouses like Seattle’s can calm people down much more effectively than the atmosphere of older, crowded ones. Devoting plenty of time and attention to cases to ensure defendants believe they are treated fairly also can help, she said.

And when all that fails, she noted, "we have a very highly trained police force in the marshals."

"You can’t be a judge very long without having a trial that presents concerning situations," Pechman said. "We handle them by talking them through with the marshals. … This sounds like something that could have happened at any courthouse, at any time."

Johnson reported from Seattle. Associated Press writers Annie Knox in Salt Lake City and Ken Ritter in Las Vegas contributed.