The Los Angeles Times said that the shooting occurred because of a dispute between the two students. Shots were first reported at about 7 a.m. local time, which is a half hour before school was set to begin, officials said.
A 15-year-old boy was shot in the head and a 15-year-old girl shot in the wrist at Sal Castro Middle School in Los Angeles on February 1, officials said.
Authorities apprehended the suspect at a Vons grocery store, about a mile from the school. A 14-year-old male student was taken into custody during a massive law enforcement response following the campus shooting that left one student with a gunshot to the arm. The weapon used, an SKS rifle, was found discarded in a field, McDonnell said.
The Los Angeles County Sheriff's Department confirmed that one gunshot victim was hospitalized after the incident. The campus was then placed on lockdown and students were told to shelter in place, McDonnell said.
Authorities said the shooting appeared to be random but have not revealed the motive.
"As I turn another corner I see the kid with the gun", George said. "Thankfully we only had one child that was shot".More news: California weighs solar-panel mandate
Highland High student Katharina Smith, 16, said she was driving to the school when she saw "a ton of police racing toward school".
"He looks back at me and tells me to run", he said. "I'm startled thinking it's one of my ROTC members". The campuses were searched and no incidents of concern were reported, the superintendent later said.
Palmdale, a city of about 150,000 people, is in Los Angeles County, about 40 miles north of downtown Los Angeles.
Deputies also responded to reports of gunfire near the Manzanita Elementary School, near the Highland High School, but the sheriff's department tweeted that the school was clear and there was no evidence of a crime. While police searched for the suspect and secured the area, the school was on lockdown.
"So I called the school and his teacher was crying, but she said everything was fine and he was fine", Guzman said.
A concerned parent waiting for her son near Highland High said she got a text from him saying he heard a gunshot and that he had locked himself in a classroom. This is reportedly the 21st school shooting in the U.S. this year.