LOS ANGELES (AP) -- Several charges against private investigator Anthony Pellicano and a co-defendant are being dropped.

A federal judge granted a prosecution request Thursday to dismiss a total of 28 charges against Pellicano and former Los Angeles police Sgt. Mark Arneson.

Assistant U.S. Attorney Dan Saunders says the government made the request because some of the alleged victims in the case weren't available to testify and other counts were redundant.

Prosecutors say Pellicano ran a criminal enterprise that used wiretaps and other clandestine tactics to dig up dirt to help his clients gain an advantage in legal and other disputes. Pellicano and four other defendants have pleaded not guilty.

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