Undercover detective foils staged robbery of Riverbank gas station

RIVERBANK -- A gas station employee has been arrested on suspicion of planning a staged robbery with an undercover detective.

Riverbank police and the Sheriff's Department learned that Lester Mangan, 42, was recruiting a partner to rob the Chevron station at Oakdale and Patterson roads while he was on duty as a clerk during the graveyard shift. Detectives arranged a meeting between Mangan and an undercover detective, deputy Andrew Winter said.

Officials said Mangan intended to rob a gas station in the Petaluma area but changed his mind after he became familiar with the business where he worked.

For two weeks, Mangan and the detective planned a scenario in which the robber would point a gun at Mangan's face and demand cash so that the staging looked real on surveillance cameras. Mangan was to wait 60 seconds before pressing the panic button and the two would split the profits evenly, Winter said.

Mangan even spoke of recent layoffs in the Sheriff's Department, suggesting it was a good time to commit a robbery. "It's disturbing to hear criminals using the struggling economy against us," Sheriff Adam Christianson said.

Mangan and the detective decided the robbery should take place Sept. 18, officials said. On that night, Mangan called the detective.

"Once he made the phone call to go through with the robbery, we considered that an overt act towards the execution of the crime," Riverbank Detective Josh Humble said in a news release.

Mangan was arrested at the Chevron after making the call. He was booked at the Stanislaus County Jail on charges of burglary, grand theft and criminal conspiracy. The conversations between Mangan and investigators were recorded.

Bee staff writer Erin Tracy can be reached at or 578-2366.