When deputies arrived to the April 17 call, they were met by manager Ernesto Huerta, 31, who told them that a man with a ski mask had put a knife to his throat.
"He told them that a man had entered the store and held him at knifepoint, ordered him to open the safe," said Kern County Senior Deputy Steven Williams.
Huerta complied with the man's orders, and the robber took off with about $1,500 in cash, said Williams.
Investigators reviewed security footage and identified the masked man as former Carl's Jr. worker Christian Orozco, 30, of Wasco.
Orozco was found with cash and the ski mask in a nearby motel room, the sheriff's office said.
Further investigation found Huerta had driven Orozco to the area, before Huerta opened the restaurant that morning. Investigators said they found evidence that showed Huerta and Orozco were going to split the money after staging the robbery, the sheriff's office said.
Inside jobs are not that uncommon.
In 2013, a manager at a McDonald's in northern California was arrested suspected of robbing his own restaurant and another McDonald's, as well.
In 2011, a pair of McDonald's employees in Delano allegedly wore ski masks and used a gun to rob the burger chain's location on Cecil Avenue. Luis Rivera, 20, was a manager there, and Toni Rivera, 18, was an employee.
And, in February, a Radio Shack employee in Clearwater, Fla., allegedly tried to rob his own store but was caught.
The Carl's Jr. manager, Huerta, was booked on suspicion of burglary, grand theft and making a false report. Orozco was booked on suspicion of burglary and grand theft.