CHICAGO - A handgun used by a 48-year-old man killed by a customer as he tried to rob a suburban Chicago tanning salon over the weekend matches the gun used in a shooting spree in October along the Illinois-Indiana border, a law-enforcement officer said yesterday.

Ballistics tests showed the gun used during the failed robbery on Saturday at an L.A. Tan in Orland Park was also used in the Oct. 5 shootings that left one dead and two wounded, said the officer, who spoke on condition of anonymity.

The robber - shot dead with his own gun after a tussle with a salon customer - was identified by police as Gary Amaya, of Rankin, a tiny farming village about 60 miles south of where the border-area shootings occurred.

Will County Sheriff's office, which took the lead in investigating the Indiana-Illinois border shootings, have said only that Amaya is a potential suspect. Spokesman Ken Kaupas yesterday declined to comment further on the case.

As recently as last week, authorities said the investigation into the border shootings had gone cold and they had no suspects. Initially, a police officer was wrongly arrested in the shootings, in which the gunman had reportedly asked one victim about honeybees before opening fire.

Amaya was killed during the Saturday-night robbery attempt by Jason McDaniel, 29, a customer who happened to walk in, Orland Park police say. In a written statement, Salon staff described McDaniel as "a true hero" and "our Superman."

Amaya had just ordered one woman inside the salon to tie up another when McDaniel walked in, police say. Amaya allegedly pointed the gun at McDaniel and ordered him to tie himself up.

McDaniel tried to reason with the robber, even offering him money and telling him that he had a baby girl at home, McDaniel has said.

As Amaya reached for rope in a bag, he put the gun on a counter: That's when McDaniel said he rushed him and snatched the gun, elbowing Amaya in the chin. McDaniel let off a shot - but the man kept coming at him. McDaniel fired again, Amaya fell and he was pronounced dead about an hour later.

L.A. Tan said it was giving McDaniel a $5,000 reward, as well as free tanning services for life for him and for his wife.

In another twist, Amaya allegedly tried to handcuff a prostitute in Chicago while she was in his truck hours before he was killed during the robbery, Orland Park Police Chief Tim McCarthy told the Chicago Tribune. She managed to get away, but Amaya fired a shot at her as she fled, McCarthy said.

In Amaya's hometown in eastern Illinois, neighbors said yesterday that he tended to keep to himself.

"He was a loner," said Marleta Stanton, 54, who lives across the street from the white-frame house Amaya lived in since his 74-year-old mother died in 2006. 74. "I mean, when he come home he never came out of the house. He never had no company - nothing."

He lost his job as a truck driver, she found out recently, but she wasn't sure precisely when or why. His mother, Dorothy Amaya, moved to Rankin - which has a gas station, two bars and about 620 residents - a few years before her death, Stanton said.

Police officer Brian Dorian initially was arrested in the October shootings, but he was released days later and cleared of any suspicion after detectives verified he'd been home logged on to his computer the morning of the attacks.

Dorian's attorneys have said that many people still viewed him with suspicion even after authorities ruled him out as a suspect.

The shootings began in the morning of Oct. 5 at a rural construction site in Illinois. The gunman shot and killed Rolando Alonso, 45, of Hammond, Ind., and wounded Joshua Garza, a 19-year-old from Dyer, Ind. Later, farmer Keith Dahl, 64, was wounded near Lowell, Ind.