SAN DIEGO -- A two-year prison term was handed down Wednesday for a letter carrier who stole mail intended for residents on his routes, then sold it to identity thieves to support his methamphetamine habit.

Kenneth Wayne Herman pleaded guilty March 15 to one felony count each of using the personal identification of another, illegally acquiring access card information, fraudulent appropriation, forgery and possession of a controlled substance.

Deputy District Attorney Keith Burt said the "integrity" of the U.S. Postal Service was threatened by the 40-year-old defendant's actions.

After Herman entered his plea, defense attorney Michael Earle said his client -- who had no prior record -- got "caught up" in the identity theft ring.

Superior Court Judge Kenneth So said a full restitution hearing could be ordered later. One victim reported losses of $16,000, the prosecutor said.

Herman was arrested Feb. 19 after a monthlong undercover operation.

Large black trash bags full of mail intended for residents in Pacific Beach and Point Loma were found during a search of the defendant's Clairemont Mesa Boulevard home, authorities said.

A broader investigation into Herman's activities led to the recovery of a significant amount of methamphetamine, cash, a stolen passport, counterfeit financial documents, guns and ammunition, and the arrests of several others, Burt said.

The investigation was triggered when San Diego police Officer Chris Leahy noticed something amiss during an identity theft arrest in another case in January. He notified the district attorney's Computer and Technology Crime High-Tech Response Team.

A man taken into custody in January turned out to be an informant who told a U.S. Postal inspector that Herman had given him a stolen credit card belonging to a resident on one of his routes, according to a search warrant affidavit.

At a later meeting, the "informant" said Herman pulled out another set of personal identifying information and said he had taken the documents from "his route," according to the affidavit.