This is an archived article that was published on sltrib.com in 2015, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Fox Lake, Ill. • Investigators in northern Illinois are hoping a $50,000 reward and new videos will help produce a break in the hunt for three men wanted in this week's fatal shooting of a police officer. A guide to key aspects of the case:

The slaying • Lt. Charles Joseph Gliniewicz, a 30-year police veteran who was on the cusp of retiring, was shot Tuesday in the village of Fox Lake while pursuing three suspicious men, authorities say. He had told dispatchers the three ran into a swampy area and requested a second unit. Dispatchers soon lost contact with him, and backup officers found him about 50 yards from his squad car with a gunshot wound. He died soon after.

The killing occurred in an open area of trees and marshland bordered by several houses on one end and a public works site on the other. Police say they've previously received several complaints about vandalism and squatters in the area, but it was not clear what brought Gliniewicz to the scene Tuesday.

The latest • Motorola Solutions Inc., which has employees who live in the area, has offered up to $50,000 in reward money for information leading to the capture and conviction of the killers. And residents and businesses have stepped forward with several more videos in addition to one earlier this week from a resident's home security system that the homeowner says shows three men.

Lake County Major Crime Task Force Cmdr. George Filenko told reporters Friday he believes the new videos are "even more relevant," and that some came from intersection traffic cameras.

He said he hadn't yet had a chance to view any of them himself because they're being analyzed and processed by the FBI and the federal Department of Homeland Security. But he said he expected to have a chance to review some of them Friday.

"We're optimistic about all of these videos right now," Filenko said, adding that the videos are from different cameras that will put a chronological "storyline together."

Authorities hope the videos will offer investigators a detailed description of the three suspects. For three days, authorities have had only a vague description of the men that Gliniewicz radioed in to dispatchers: Two are white, the other is black.

Chasing leads • Filenko says investigators are getting so many tips by phone, email and social media that a second detective has been tasked with filtering through them. Authorities believe there's a strong possibility the suspects are still in the general area, and detectives are depending on the public's help.

Among the tips was one about three men seen leaving a gas station in Michigan. The car they were in turned out to have been stolen in the greater Chicago area, Filenko said.

Filenko has more than 100 people actively deployed to investigate on the ground.

Nerves rattled • Fox Lake is nestled in one of the state's most popular recreational areas, a boating and fishing playground known as the Chain O' Lakes. It's especially busy during Labor Day weekend, usually drawing tens of thousands of visitors.

But concerns mounted that tourists might decide to go elsewhere because of the heavy police presence and fear that the fugitives could be hiding somewhere among the lakes, wetlands and forests.

Mourning a popular officer • Gliniewicz, a 52-year-old tattooed officer with a shaved head, was known around town as "G.I. Joe."

Gliniewicz was planning to retire at the end of the month.

His funeral will be at 1 p.m. Monday at Antioch High School.