(CNN) -- Police said Thursday that evidence and a surviving victim tie a man killed while trying to rob an Illinois tanning salon to a two-state shooting spree earlier this year.
Gary Amaya, 48, was killed Saturday after he walked into LA Tan salon in Orland Park, Illinois, brandishing a .38 Colt revolver. A customer, Jason McDaniel, rushed at Amaya and killed him after turning the gun on him, according to surveillance video.
Will County, Illinois, Sheriff Paul Kaupas said Thursday that the weapon used by Amaya in this weekend's botched robbery was similar to the one used in two shootings October 5 along the Illinois-Indiana line. One person was killed and three were wounded in those shootings, police have said.
In addition, Amaya's vehicle outside the Orland Park shooting matched one seen in Washington Township, Illinois, and Lowell, Indiana, where the October incidents took place, Kaupas said. The Indiana survivor, too, told detectives it was Amaya who shot him.
"The evidence at this time ... tells us that the suspect that was killed in the armed robbery at Orland Park ... does match the information from the previous homicide-slash-shooting in Lowell, Indiana," Kaupas said.
Yet Kaupas did not go as far as saying definitively that Amaya was behind all three shootings, noting that he was awaiting results of more forensic tests.
Police on Thursday did not expand on widespread reports that the gunman in the first two shootings randomly discussed honey bees before shooting his victims -- leading media to brand him "the Honey Bee Killer." But Kaupas did say Amaya previously worked at a hunting lodge in rural Grundy County, Illinois, where he cared for honey bees.
Authorities also elaborated on Saturday's botched robbery and shooting.
Orland Park Police Chief Tim McCarthy said McDaniel, who was in the shop with a worker, offered Amaya his money and explained that he had a young child.
"The comment by Amaya was, 'Whatever,'" McCarthy said at the Thursday news conference. "At that point, both feared for their life, that this was going to be more than a robbery."
Video shows McDaniel, 29, rushing at robber and, during the struggle, Amaya being shot. McDaniel told CNN affiliate WGN that he acted after coming to the conclusion that there was something wrong with Amaya.
"There was no ... hurry," McDaniel said. "He was very calm, like he wanted to hurt somebody -- like that was his intended goal."
This weekend's shooting come more than two months after a gunman killed one construction worker and hurt two in Washington Township.
An hour later and about 10 miles away in Lowell, Indiana, authorities believe the same gunman struck again -- this time firing on a farmer. Keith Dahl was shot in the left shoulder, arm and elbow, and then was robbed.
The farmer talked with police detectives after this weekend's incident.
"Mr. Dahl has unequivocally identified Gary Amaya as the person who shot him," Lake County, Indiana, Sheriff Roy Dominguez said at Thursday's news conference.
Amaya is not the first person arrested in connection with the October shootings.
Lynwood, Illinois, police officer Brian Dorian was charged with first-degree murder, but four days later was released from jail after authorities were able to verify his alibi.
"I feel horrible that Brian Dorian went through this," said Will County State's Attorney James W. Glasgow. "At no time did we stop looking for exculpatory evidence."