CHICAGO (CBS) — A Cook County jail guard has been charged with murder, and the sheriff’s office is taking steps to fire him, in connection with a deadly road rage shooting in Hammond.

On Thursday, 23-year-old Montrell Moss was shot and killed, after throwing a cup of water at a van that had twice cut him off along Indianapolis Boulevard in Hammond, Ind.

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The van driver pulled out a 9mm gun, shooting Moss in the neck. Moss then drove his car into a gas pump at a nearby gas station. He died there at the scene.

Montrell Moss (Family Photo)

Montrell Moss (Family Photo)

Officers questioned a witness from Moss’ car, who pointed to a passing van as he was speaking to police. Officers stopped the van, and found a gun and shell casing inside.

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On Saturday, 61-year-old Edgar Singleton Jr. was charged with one count of murder, and was being held in the Lake County (Ind.) jail, reports the Northwest Times of Indiana.

Singleton works as a correctional officer at Cook County Jail.

“The Cook County Sheriff’s Office has de-deputized Mr. Singleton and is in the process of terminating his employment,” the sheriff’s office said in an email on Sunday.

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Court information for Singleton was not immediately available Sunday afternoon.