PALMDALE, Calif. (AP) - A 14-year-old used a rifle to shoot a classmate in the arm Friday at their high school in California and dumped the gun in the desert before he was caught in a shopping center, authorities said.

The shooting at Highland High School in Palmdale was sparked by a dispute between the two students, officials said.

Investigators were still trying to determine a specific motive.

The victim, also 14, was taken to the hospital and is expected to make a full recovery, said Nicole Nishida, a Los Angeles County sheriff's spokeswoman. She said the suspect was found in the shopping center.

Garret Root, a teacher at the school, told KNBC-TV that he was walking up to the school when he saw a group of students running away and asked them what was happening.

"They said there was a shooter," Root said. "At first I didn't believe them, but then I heard a gunshot.

He said he saw what looked like a boy, about 100 yards away, carrying a long gun.

The lockdown at the school was lifted several hours after the shooting and school officials said they would begin reuniting students with their parents.

The FBI and agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives also responded to the scene.

Sheriff's deputies also received a call reporting shots fired in the vicinity of Manzanita Elementary School about 7 miles (11 kilometers) away from Highland High School.

Officials said deputies searched the elementary school and found no evidence of a shooting.