A man who allegedly stabbed a 15-year-old to death at a California secondary school drove into the car park and tried to grab two girls before knifing one of them, a school official said.

Anthony Gray, 52, is accused of murdering Alycia Reynaga at Stagg High School on Monday.

He was charged on Wednesday and refused bail.

San Joaquin County district attorney Tori Verber Salazar told reporters Gray faces the possibility of life without parole.

“As a mother, this seemingly random act of violence is devastating,” she said, sending her condolences to Alycia’s family.

The teenager was stabbed several times at about 11am and taken to hospital, where she died, Stockton Unified School District superintendent John Ramirez said.

Officials have not determined a motive.

Stockton Unified spokeswoman Melinda Meza said there is no known connection between Gray and Alycia, a first year student who played softball.

“I’ll always have that empty space in my heart,” Lia Medrazo, the school’s softball coach told KOVR-TV.

“The girls are going to miss her and I hope her sister comes back and wants to play for her.”

Stockton is a Central Valley city about 60 miles east of San Francisco.