OAKLAND — A fired armored truck guard has been arrested and charged with murdering his former colleague during a robbery at the Kaiser building in San Leandro, court records show.

Akbar Bey, 27, was charged Thursday with murdering 60-year-old John Mendez in a Sept. 7 shooting, with enhancements alleging the crime involved “planning, sophistication, or professionalism.” He is also charged with robbing Mendez’s GardaWorld truck.

Police allege that Bey and Mendez were once partners who worked the same route for GardaWorld as recently as July, and that Bey and another man were fired for allegedly stealing from the company. Because of this, they say Bey had insider knowledge of the route Mendez was working that day.

The shooting and robbery happened about 11:40 a.m. Sept. 7 on the hospital grounds, located at 2500 Merced St. Mendez was pronounced dead roughly three hours later.

Bey allegedly waited for Mendez to exit the vehicle, shot him in the back of the head, then made off with a courier bag full of cash. Police say he was seen getting into a black Honda and driving away. Authorities later linked the Honda to the other former GardaWorld employee who had been fired along with Bey, but he has not been charged in the robbery and homicide, according to court records.

Detectives conducted surveillance on Bey on Sept. 20 and saw him wearing clothing similar to the shooter. GardaWorld managers identified Bey from a photo taken during that surveillance, authorities say.

Bey is being held without bail at Santa Rita Jail in Dublin. His next court appearance has been set for Oct. 21, where he is set to enter a plea, records show.

Authorities allege that after the incident Bey bought a Porsche.

The shooting was one of two armored car robbery-homicides to occur in the East Bay last month, the other being a Sept. 23 incident in Oakland where four men allegedly attempted to rob a Brinks truck. In that shooting, a Brinks employee killed one of the suspected robbers and wounded another, before being shot by one of the robbers, police say. The Brinks employee survived and a Vallejo man was arrested and charged last week with murder.