By Devin Fehely

SAN JOSE (KPIX 5) — A quick-thinking security guard is being credited with stopping an alleged sexual assault in progress at a shopping center in San Jose on Monday.

“I noticed him in the back with a minor. I noticed the age difference right away. And obviously, I knew there something was wrong,” said security guard Christopher Gomez.

READ MORE: UPDATE: Brush Fire Burns In North San Jose, Milpitas Along Coyote Creek Area

Gomez says he was patrolling an area behind the shopping center on East Capitol Expressway. Gomez says cars are not supposed to park behind the shopping center.

So when 70-year-old Tuan Nguyen parked in the secluded area and got into the backseat of his minivan, Gomez says it caught his attention. He went to investigate and made a shocking discovery–there was a young girl in the backseat as well.

“When I asked her what her age was, she said she was 13. I asked, ‘You OK?’ She just gave me a blank stare and she just said, ‘No.'” Gomez said.

READ MORE: Report: Windows Broken At Gov. Newsom's Family-Owned Wine Shop In San Francisco

Gomez says he aspires to be a police officer someday. He says his actions in that moment were a combination of his training and his reaction as a father.

“I told him you need to step out of the vehicle. He refused. That’s when I drew my weapon and had him step out of the vehicle. He came out,” Gomez said.

He said the subject initially pretended not to understand English. “I handcuffed him properly and called San Jose PD. They came out and did their job.”

San Jose police say Nguyen worked as a driver, dropping off and picking up several children from school. He allegedly dropped off several other children first Monday, leaving himself alone with the victim.

MORE NEWS: COVID: San Francisco's City Employee Vaccine Mandate Is Not A First In America

“She was in shock–definitely in shock. She wasn’t in the right state of mind. After she got out of the vehicle is when she kind of lost it,” Gomez said.