Houston police are searching for a suspect in robbery-turned-murder that killed a high school student who worked at a Subway restaurant with his mother.

The Houston Police Department told CBS News that 18-year-old Javier Flores and his mother were both working a shift at a Houston Subway on Monday when an armed robbers entered the store, pointing a gun at the head of an employee believed to be Flores’ mother.

“[Flores] tried to intervene and when he confronted the guy with the gun, he was shot.” Detective David Crowder told CBS News.

Flores was taken to a nearby hospital but did not survive.

The suspects are believed to be two young black males: One is about 17 years old and six feet tall with a slim build; he is believed to be the shooter.

A second suspect is described as 18-20 year old and 5’6″ to 5’8″ tall.

Both suspects were wearing hoodies and dark pants, and were reportedly driving a gold four-door sedan. Police believe said they matched the descriptions of suspects in a second Subway robbery the same night.

Houston CBS affiliate KHOU interviewed classmates of Flores at Cesar Chavez High School.

“He was a good, really good friend,” said Helizander Rodriguez. “He took a bullet for his mom.”

“I call him my hero just for doing that,” said Endy Herrera.

Anyone with information on the suspects is urged to call Houston Crime Stoppers at 713-222-TIPS.