Lane Garrison, who pleaded guilty to vehicular manslaughter and drunken driving in a crash that killed a teenage passenger, was ordered Thursday to undergo a 90-day evaluation to help a judge decide his sentence.

The former "Prison Break" actor will undergo a "diagnostic" by parole officers and psychologists in a prison before returning for an Oct. 31 appearance before Superior Court Judge Elden S. Fox.

Garrison, 27, was driving a 2001 Land Rover on Dec. 2 when he lost control and rammed a tree. The crash killed Vahagn Setian, a Beverly Hills High School student who would have been 18 on Wednesday. Two other passengers, both 15-year-old girls, survived. They testified at the sentencing.

Garrison had a blood-alcohol content of 0.20 percent, more than twice the legal limit for driving, and was under the influence of cocaine, according to police.

Dozens of the victim's friends and relatives were in court, many wearing T-shirts with Setian's picture on the front and the James Dean saying, "Dream as if you'll live forever, live as if you'll die today" on the back.

About 20 people attended in support of Garrison.

The actor pleaded guilty in May to one count of vehicular manslaughter without gross negligence, one count of driving under the influence with a blood-alcohol level of 0.15 percent or higher, and a misdemeanor of providing alcohol to a minor.

Garrison faces a maximum sentence of six years, eight months in prison. The Los Angeles County district attorney's office has asked for four years and eight months.

He cried during the hearing and apologized to Setian's family.

"I relive that night every day, and I think about the bad decision I made that day. All I can say to you is, I'm so sorry," he said.

Garrison had been free on $100,000 bail but was held in custody after Thursday's hearing.

His character on Fox's "Prison Break" was killed in the show's Oct. 2 episode. The Dallas native's other credits include the film "Crazy."

He was recently featured in a public service announcement that encourages viewers not to drink and drive. The PSA re-enacts his crash and he appears to be holding back tears as he talks about what a stupid and costly mistake he made.

Setian's father, Karen Setian, told the judge he believed the PSA was Garrison's attempt to appear sympathetic before sentencing.

"He is an actor, and he is acting. Let's not fall for his act," he said.

He said his son was killed "not by an accident but by the reckless action" of Garrison.

"In mere seconds, our hearts and our souls were ripped apart," he said.