The California Highway Patrol said Jerimiah Hartline, 19, of Tennessee stole the semi from a weigh station on Interstate 15 in Rainbow around 6 p.m. Saturday and drove it to Temecula, where he collided with a Toyota Tacoma that in turn struck a Toyota 4-Runner and a Mercedes, The (Riverside) Press-Enterprise reported Wednesday.
Investigators said Hartline struck two other cars before losing control of the truck, which flipped onto its side and blocked all four northbound lanes of the interstate.
Highway Patrol spokesman Nathan Baer said Hartline climbed into a van and demanded a ride, but the driver instead pulled him out of the vehicle and held him with the help of other bystanders until officers arrived.
Police said Hartline, who was a passenger in the semi before driving off at the weigh station, denied ever being behind the wheel of the truck and gave a different explanation for demanding a ride from the van driver.
"He said zombies were chasing him and he had to get out of here," Baer said.
Baer said police have yet to determine whether Hartline was under the influence of drugs.
The spokesman said police are seeking vehicle theft and hit-and-run charges against Hartline.