CASTLE ROCK, Colo. (CBS4)– A sergeant with the Douglas County Sheriff’s Office has been fired after more than 20 years after it was revealed that he was convicted of killing someone.

Gary Butler was convicted of manslaughter in Utah after he shot and killed the St. George, Utah police chief’s brother in a love triangle in 1975.

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Once Douglas County Sheriff Tony Spurlock learned of the conviction, Butler was fired. He had served 21 years in the sheriff’s office.

“He committed a felony. He committed a heinous crime, in my opinion. He should have disclosed that information to us when he was applying,” said Spurlock.

Gary Butler (credit: Douglas County Sheriff)

Gary Butler (credit: Douglas County Sheriff)

Apparently Butler had recently spoken to another employee at the Douglas County Sheriff’s Office and mentioned his conviction for manslaughter. That employee then told the internal affairs division which conducted an investigation.

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Butler didn’t have to disclose his conviction because he was able to get the manslaughter conviction legally removed from any court records. That was before the modern technology.

In an online search, CBS4 Investigator Rick Sallinger was quickly able to find a Utah Supreme Court decision where Butler lost his case. He spent three years in prison.

When asked if they did a thorough enough background check when he was hired, Spurlock answered, “In 1991, yes, we did. Based upon what he put on his application and based upon the laws that were applicable at the time.”

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Butler also failed to disclose that he had worked for the St. George Police Department.