CHICAGO (CBS) — A popular Fox Lake police officer conducted a “carefully staged” suicide two months ago after engaging in “extensive criminal acts” over several years, investigators said on Wednesday.

Lake County Major Crimes Task Force Commander George Filenko said Lt. Joe Gliniewicz was being investigated for stealing money from the Fox Lake Police Explorer training program. He said the amount of money taken was “thousands of dollars” for personal use over the past seven years.

RELATED: In texts, Gliniewicz says: ‘I am pretty well f—–‘

Investigators believed Gliniewicz was under increasing stress, fearing that his activities were being exposed by Fox Lake Village Administrator Anne Marrin, who had begun to ask questions about how the program’s money was being used.

On Wednesday, Marrin said Gliniewicz threatened her as she began her audit of the Explorer program, which is used to train young people who may be considering a career in law enforcement.

“This episode has left us unsettled and uneasy,” Marrin said. “The community is the real victim here.”

The officer apparently used the money for travel, gym memberships, personal loans, adult websites and other personal items.

“This extensive investigation has concluded with an overwhelming amount of evidence that Gliniewicz’s death was a carefully staged suicide,” Filenko said.

Investigators believe two others were involved in the criminal activity but their identities have not been released. Multiple published reports say that Gliniewicz’s wife, Melodie, and son DJ are being questioned.

Gliniewicz, 52, was found on the morning of Sept. 1. He had radioed in a short time before that he was in pursuit of three men. The shooting led to a massive manhunt for the suspects and a drawn out probe into the death.

Gliniewicz was shot once on the right front side of his protective vest, and once in the upper chest with his own service weapon. His death was initially investigated as a homicide.

At a news conference, Filenko provided some more details that showed the officer’s elaborate attempts to set up a struggle at the scene. Gliniewicz had extensive experience in setting up crime scenes as part of the Police Explorer training program.

Filenko said investigators first found a can of pepper spray and then a short distance from there, the officer’s baton. His eye glasses were found separately from his body, along with a shell casing.

Filenko said investigators believe Gliniewicz placed his glasses on the ground and shot himself in his vest and then moved a short distance to fire the fatal shot.

Originally, the investigators were focused on solving a homicide, Filenko said. However, as they began to examine the officer’s text messages over the past six months and then personal bank statements, investigators began to unravel Gliniewicz’s criminal activity.

Forensic tests found gunshot residue on Gliniewicz’s hands, but investigators earlier said those tests were inconclusive in determining whether Gliniewicz fired the weapon, or if his hands simply were near the gun when it was shot.

According to the coroner’s report in the case, the first shot – which struck Gliniewicz’s vest – would have hit him with force similar to a sledgehammer. The second shot missed his vest, and struck him in the upper left chest, killing him.

Gliniewicz died near U.S. Route 12 and Sayton Road. Police have said he was investigating suspicious activity in the area, and radioed that he had begun chasing three suspects. A few minutes after backup officers arrived on the scene, they found his body.

Police have said Gliniewicz provided only a very vague description of the three suspects – two white males and one black male.

Investigators found indications of a struggle at the scene.

During the course of the investigation, police took 100 DNA swabs from various people, including anyone interviewed in connection with the case, and anyone who had direct or indirect contact with Gliniewicz, or who was near the crime scene on that day – including every police officer who was close to the scene.

The officer’s family released a statement saying, “Today has been another day of deep sorrow for the Gliniewicz family. The family has cooperated with the Task Force’s investigation and will not comment at this time. The Gliniewicz family requests that their privacy be respected as they continue to cope with the loss of the beloved husband and father.”