LOS ANGELES (CBSLA) – A Los Angeles police officer charged with using a gun in an assault outside an El Segundo bar while off-duty last year was arraigned in a downtown L.A. courtroom Tuesday.

Joseph William Rooney, 33, pleaded not guilty in Los Angeles Superior Court to four counts of assault with a firearm in the attack that occurred on May 22, 2016.

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According to the L.A. County district attorney’s office, Rooney approached three men as they were leaving a bar, pulled out a handgun and struck one of the men in the face with it. He then pointed the gun at the two other men. The motive in the attack was unclear.

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It was not confirmed if Rooney remains on active duty. An LAPD spokesperson told the Los Angeles Times that he was last assigned to the Newton Division.

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Rooney’s next court hearing is scheduled for Oct. 31. If convicted, he faces a maximum sentence of 27 years in state prison.