And now, authorities are looking at Lt. Joe Gliniewicz's wife and son to determine whether they were involved in the thefts, three law enforcement sources told CNN.
Gliniewicz's file shows at least five suspensions, 10 violations of department rules and procedures, and accounts of three notable incidents -- including one in which he threatened a colleague and another in which he was found passed out in the driver's seat of his personal vehicle, "with the engine running full throttle with his foot on the gas." In the third case, commanders accused him of leaving a crime scene unattended, according to the documents.
Gliniewicz killed himself September 1 after radioing dispatchers that he was chasing three men and later radioing for backup, according to investigators.
Although authorities initially thought he'd been gunned down by the fleeing suspects, they later concluded he killed himself after stealing thousands of dollars from the Police Explorer post he helped run.
Investigators also say Gliniewicz discussed meeting with a gang member, possibly to arrange killing the village administrator in Fox Lake, with whom he said he had clashed over the Explorer program and its assets.
He also had an "arrestable" amount of cocaine in an unmarked evidence bag in his office. In a text message, Gliniewicz had discussed planting evidence on Village Administrator Anne Marrin, according to investigators -- leading to speculation the cocaine might have been for that purpose. Investigators never found evidence to back that theory, however.
In a news conference Thursday night, Marrin called the allegations "unsettling," saying she had never fought with Gliniewicz or even had harsh words with him.
"Even though these threats were made months ago, I take these threats very seriously," she said.
Shooting theory undone by bank records, texts
Although community leaders and members of Gliniewicz's own Explorer post lauded him
in the days following his death -- at that point thought to be a possible homicide -- the police investigation has since shown that Gliniewicz stole thousands of dollars from the Explorers Post, an organization for youths interested in law enforcement, authorities said.
Text messages -- deleted by Gliniewicz, but meticulously recovered by police over several weeks -- and bank records confirmed the embezzlement, according to George Filenko, commander of the Lake County Major Crimes Task Force.
The police department sponsored the group, and Gliniewicz was the leader. Investigators said he used the money to pay his mortgage, access to adult websites, travel and other expenses.
On Thursday, a law enforcement source told CNN that Gliniewicz discussed using funds from the Explorer account in text messages with his wife and son.
In one text message, Gliniewicz wrote that he "used the exploder account" -- an apparent reference to the Explorer Post's bank account -- to pay for a $624 airline flight. In another, he wrote: "You are borrowing from that 'other' account, when you get back youll have to start dumping money into that account or you will be visiting me in JAIL!!"
Shortly before his death, Marrin said she asked for an inventory of equipment owned by the Explorers. He didn't provide it by the deadline she had said, and killed himself the day she reiterated her request, according to officials.
"This village administrator hates me and the explorer program. This situation right here would give her the means to CRUCIFY ME if it were discovered," he said in an undated text message asking one of the people identified by investigators as family members to begin making payments into the account "very soon."
No one else has been charged in connection with the funds. An attorney for the family declined comment when reached by CNN.
While the embezzlement allegations and revelations involving the village administrator are the most sensational, personnel records show Gliniewicz had several lesser issues in his 30-year career with the department.
The file shows he was suspended three times between 1987 and 1999, once for an unspecified reason, once for failure to report for duty and once for a rules violation that resulted in damage to city property. He was again suspended in 2012 in a dispute over a police report and again in 2013 for being late.
The personnel file also includes notes involving at least 10 violations of departmental rules, including calling in sick when he wasn't, being late, not following proper procedures for prisoner movements and changing his administrative privileges in a records system to a higher level without authorization.
The file also details an incident in which another law enforcement official reported finding Gliniewicz passed out in the driver's seat of his truck, the engine revving, and was unable to wake him.
"This Deputy told me that this was not the first time that something like this has happened," an official wrote in a report on the incident.
In another incident, Gliniewicz made a threatening comment to a colleague that included the phrase, "faster than I could put three rounds of bullets in your chest."
He also left a crime scene unattended, according to the personnel file. "The risk of the destruction or altering of evidence or the entire crime scene is unacceptable and outrageous," an official wrote in the file.
The file also contains an unsigned, anonymous letter from members of the department complaining about Gliniewicz's behavior, including claims of sexual harassment and an "inappropriate sexual relationship" with a subordinate.
The file also includes many certificates for class completion as well as good reviews.
'I had nothing to do with it'
The final act of his career played out September 1, when Gliniewicz radioed that he was pursuing a trio on foot.
He described three possible suspects.
"I'm out near the old concrete plant checking out two male white, a male black," Gliniewicz radioed, according to CNN affiliate WLS.
Three minutes later, he requested backup. It was the last time anyone would hear from him.
Backup arrived minutes later and found him dead of what his autopsy would later reveal to be a gunshot wound to the chest.
A massive manhunt followed as 400 law enforcement officers scoured the woods looking for his killers.
That manhunt nearly snared Thomas Corso and his friends -- whom Corso said resembled the three men Gliniewicz described in his radio call.
"There was a great possibility that Lt. Gliniewicz may have driven by those three individuals on his way to that scene," Cmdr. Filenko told WLS at the time.
Corso said they were using the ATM at the time.
A few days later, authorities questioned Corso and his friends.
Investigators cleared the three after they presented receipts from a diner and witnesses confirmed seeing them there.
Corso said Thursday said he didn't even know about what had happened to Gliniewicz until someone told him a huge manhunt was underway. It's been stressful, he said.
"Oh absolutely, this is a big relief for me, when I got the news yesterday, it was a huge relief," he said.