12/04/2006 at 10:15 PM EST
actor Lane Garrison "displayed symptoms of alcohol intoxication" after being involved in a fatal car crash
on Saturday, police said in a press conference Monday, but no charges have been filed.
Garrison, 26, who plays "Tweener" on the FOX jailhouse drama, was driving his Land Rover SUV, with three teenagers riding in it, when the vehicle struck a tree at 11:52 p.m., killing a 17-year-old male passenger. The teen's identity has not been revealed.
Police say investigators removed alcohol containers from the vehicle, which was registered to the actor.
Garrison's attorney, Harland Braun, says the actor, who was taken to Century City Hospital for treatment of minor injuries, had a margarita with dinner but was not driving under the influence and was knocked unconscious in the accident. Instead, Braun pointed to a possible problem with the brakes in the SUV.
After the accident, two 15-year-old girls who were also in the car were transported to Cedars-Sinai Medical Center. One has been released from the hospital; the other is in serious condition.
Braun says Garrison had met the teens that night at a grocery store, where they invited him to attend a party. At the time of the accident, he says, the group was leaving the gathering and he was driving them back to a grocery store.
In an interview with PEOPLE in May, Garrison said he had a somewhat troubled past. "I should really be in prison," said Garrison, who, as a teen, "stole everything I could get my hands on: I stole cars, stole stereos."
At 15, after a botched attempt to filch a jug of wine from a stranger's garage, he ran home, where, he says, "my mother just slapped the crap out of me. She drove me to the police station. The cops handcuffed me and put me in a cell to scare me." Sentenced to community service, he said, "I mowed probably every lawn in my city."
After having trouble getting along with his mother, Garrison left home at age 17 and moved in with his family's minister – Joe Simpson, father to Jessica and Ashlee Simpson.
"I'm very grateful to him," said Garrison, adding, "Jessica and I grew up together." Though they remained just friends, "it was torture for me," he joked at the time, "because Jessica was gorgeous."
After Garrison's accident, the singer issued a statement through her rep saying, "Jessica and her family love Lane very much and he is in their thoughts and prayers."