LOS ANGELES (CBS) — A yearlong Federal Undercover operation ended Wednesday morning with multiple arrests and the shutdown of a major illegal gun trafficking operation in Southern California.

“Operation Woodchuck” began last year after federal agents were tipped off to the gun selling ring and began an undercover investigation, according to officials with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).

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KNX 1070’s Pete Demetriou reports.

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“We ended up buying over 50 guns in an undercover capacity . . . ranging from sawed off shotguns to high caliber weapons, such as SKS’s, M1’s and even bought a machine gun with a silencer from these individuals,” said John Torres, Special Agent in Charge of the ATF office in Los Angeles.

In all, 58 firearms were seized, the Associated Press reported.

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Eight of the12 people named in a grand jury indictment for illegal firearms trafficking were arrested and are in federal custody. One of the suspects was arrested on state charges. Authorities are searching for three remaining defendants.