EL MONTE >> A reward for information leading to justice for an El Monte man shot to death during a botched robbery at a Jack in the Box restaurant last month continues to grow, as city officials in El Monte and Jack in the Box representatives have announced plans to add to a $20,000 reward already offered by the Los Angeles County Board of Supervisors, authorities said.

Juan Miguel Vidal, 25, was working at the restaurant about 7:30 p.m. on Oct. 21 when the unidentified, masked gunman jumped over the counter of the restaurant, 9220 Flair Drive, demanded money and immediately opened fire, Los Angeles County sheriff’s officials said.

•Video: El Monte fatal shooting

Vidal, who was engaged to be married and had recently graduated pharmacy technician school, died from his injuries at a hospital, officials said. His killer fled empty-handed and remains at large. An accomplice believed to have served as the getaway driver of a dark-colored sedan in which the shooter fled is also being sought, Detective Adan Torres of the sheriff’s Homicide Bureau said.

In hopes of generating tips from the public, the Los Angeles Count Board of Supervisors authorized a $20,000 reward for information leading to the arrest and conviction of those responsible for Vidal’s slaying on Wednesday.

The El Monte City council plans to announce the city will be contributing to the award amount during a press conference on Monday, according to El Monte police Lt. Christopher Cano. The amount the city will be adding was not available.

“Additionally, John Maki, owner of the franchised Jack in the Box restaurant where Juan Vidal worked, and Oscar Hurtado, representing Jack in the Box corporate, both added $5,000.00 dollars each to the reward,” Cano said in a written statement.

Anyone with information is asked to contact the sheriff’s Homicide Bureau at 323-890-5500. Tips may also be submitted anonymously to L.A. Regional Crime Stoppers at 800-222-8477.