The Illinois police officer whose shooting death triggered a massive manhunt in September died from a "carefully staged suicide," according to investigators.

Fox Lake Police Lt. Joe Gliniewicz took his own life because he realized a financial audit would soon reveal that he had been stealing and laundering police funds using forged signatures on documents, according to Lake County Major Crimes Task Force Commander George Filenko.

"This staged suicide was the end result of extensive criminal acts that Gliniewicz had been committing," Filenko said at a news conference Wednesday.

Lt. Gliniewicz was buried with honors as a fallen law enforcement officer, investigators realized weeks later that he had a motive for suicide.

He had been stealing from a program he was in charge of that trained young police officers. He allegedly used the money to pay his home mortgage and other bills. But he realized an "audit would eventually lead to discovery of his financial malfeasance," Filenko said.

He was trained in staging mock crime scenes, which helped him make his suicide appear to be at the hands of unknown criminals.

His last radio call at 7:52 a.m. on the morning of September 1 said he was chasing three male suspects on foot. He called for back up three minutes later. Officers responding to his call for back up found him dead about 50 yards from his patrol car, police said.

A security camera recorded three people near the scene, but investigators later cleared them.

Two shots had been fired from Gliniewicz's .40-caliber service pistol, including one that was found lodged in his bulletproof vest and another that entered his torso.

A massive manhunt involving 400 law enforcement officers searched the dense woods near the scene for clues. Federal, state and nearby local law enforcement agencies joined the search and probe, which ended after several weeks with no suspects identified.

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