An off-duty San Diego police officer is expected to survive a gunshot wound to the back of his head sustained when he was robbed at an ATM machine.

Escondido police Lt. Craig Carter says the 57-year-old officer was shot shortly after noon Monday in the north San Diego suburb. The assailant, who was wearing a baseball cap with "police" on it, escaped with the officer's wallet, cell phone and an undisclosed amount of money.

Police say the officer is hospitalized in good condition. The bullet appears to have struck his skull and traversed around the side of his head.

The officer a 27-year veteran of the force. His name has not been released.

The U-T San Diego reports that the same suspect may have committed two other robberies earlier Monday.