APPLE VALLEY (CBSLA.com) — A man identified as a former California Highway Patrol officer was killed Monday night in a shootout with San Bernardino County Sheriff’s Department deputies.

Francis Murphy Rose patrolled the highways of the Barstow area until 2013, when he was assaulted on the job by a man under the influence of drugs. Shortly after that incident, Rose went on disability.

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Rose’s friend Michael Mazolla says the event changed him mentally.

“Ever since then, he kind of had these demons on him that just bothered him, because he didn’t feel like he was doing the right thing,” Mazzola said. “He just wanted to help people … always help people.”

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Mazolla says that Monday night, those demons may have gotten the best of his friend.

Deputies responded to Rose’s hilltop home in Apple Valley in the 9000 block of Buena Vista street after receiving calls of shots being fired. They say Rose began firing at officers on the ground and at a helicopter.

Deputies returned fire, and Rose was killed in the exchange.

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The CHP says Rose graduated from the academy in 2009.