FOX LAKE, Ill. -- As the manhunt for three suspects wanted in the fatal shooting of a popular Illinois police officer intensifies, new video that possibly shows the suspects is being analyzed, according to Lake County Major Crimes Task Force Cmdr. George Filenko, the lead investigator on the case.
"I think we are optimistic about all these videos right now," said Filenko during a press conference Friday.
Lt. Charles Joseph Gliniewicz, a 30-year police veteran only a month from retirement, was shot Tuesday morning while pursuing the men he spotted on his way to work, said Filenko. Gliniewicz told dispatchers the three ran into a swampy area, and he requested a second unit.
Dispatchers soon lost contact with him. Backup officers found him about 50 yards from his squad car with a gunshot wound. He died soon after.
Filenko said there was no indication he was intentionally targeted, though authorities did not rule out that possibility.
"We are still looking, going back, going back again," said Filenko. "We are revisiting a number of things."
During the press conference on Friday, Filenko said the officer's weapon has been recovered at the scene. The new video being analyzed comes from businesses and residents.
Investigators had previously said they were reviewing video recordings, but so far none has captured images of the suspects. Filenko said this is new video being reviewed.
A major challenge facing authorities was the lack of a description of the suspects beyond the vague one that came from the officer, who told dispatchers he was pursuing three suspicious men -- two white, one black -- moments before he was shot.
"That was the only description provided," said Filenko. "So of course we're getting the public calling in every time they see that match of three individuals or even two individuals. We've closed out those leads completely as being unsubstantiated."
Asked by CBS News correspondent Anna Werner how dangerous the suspects are, Filenko replied, "They shot a police officer, so I think that speaks for itself -- extremely dangerous."
Authorities broadened the hunt Wednesday, acknowledging they had no indication the men were still in the area where the slaying happened.
After an intensive 14-hour "grid search" of homes, railroad tracks and marshland in the village of Fox Lake, the second-day of the manhunt turned to the painstaking detective work of chasing down tips, collecting and reviewing surveillance video and interviewing residents near the crime scene.
Meanwhile, new search teams rippled out into subdivisions beyond the initial 2-square-mile perimeter established Tuesday. At least 100 investigators were on the ground.
Wednesday night, authorities responded to a report of two "suspicious subjects" running through a corn field in the Chicago suburb of Volo, about 5 miles from Fox Lake, Lake County Sheriff's Office spokesperson Detective Christopher Covelli told CBS Chicago.
Police officers with dogs conducted systematic searches with air support, although there was no evidence the report was related to the shooting suspects, Covelli said. Officers didn't spot anyone during the search, he said.
But he added, "Given the circumstances, we're taking it very seriously."
Later, Covelli issued a statement saying the report was a hoax by a local nanny seeking attention from the family she works for. Kristin B. Kiefer, 30, is being charged with two counts disorderly conduct -- falsifying a police report.
During the press conference, it was announced that the FBI will be offering a fully staffed and functional tip line. Motorola Solutions is also offering a $50,000 reward for any information.
The phone number for those with information about the suspects is 1-800-CALL-FBI. There is also a website setup by the FBI for tips as well.