AURORA, Colorado — A Nevada inmate previously convicted of attacking a couple with an ax handle in their bedroom is now suspected of killing four people with a hammer in two attacks in suburban Denver more than 30 years ago, authorities said Friday.

Law enforcement officials said DNA evidence has tied Alexander Christopher Ewing to the slayings of Patricia Louise Smith, 50, in Lakewood, and three members of the Bennett family in Aurora in 1984.

A hammer was used to kill Smith, a mother and grandmother who was attacked while eating lunch on Jan. 10, 1984. The weapon was left in her condo.

About a week later, a different hammer was used to kill Bruce and Debra Bennett, 27 and 26, and their 7-year-old daughter Melissa at their home in Aurora, about 15 miles from Lakewood. The couple's 3-year-old daughter, Vanessa, was severely injured.

Ewing has been behind bars in Nevada since the summer of 1984 after he escaped there while being transported to Kingman, Arizona, from St. George, Utah, for a court appearance on attempted murder and burglary charges.

His sentence runs through 2037, but he could be eligible for parole in 2021.

Colorado prosecutors said Friday they were preparing papers to extradite Ewing — a process that could take months — and that possible charges in the Colorado deaths could carry the death penalty.

Nevada authorities notified Colorado officials of a possible DNA match in early July. The news "sent a chill through my spine," said John Camper, director of the Colorado Bureau of Investigation.

Camper credited consistent advances in DNA technology over the decades in leading to a match.

The first DNA samples collected from the attack on the Bennett family were uploaded to an FBI database in 2001, Camper said. In 2010, the Colorado Bureau of Investigation developed a DNA profile in the Smith killing that matched the Bennett case, he said.

In July, under a new state law that requires DNA sampling of inmates, Nevada authorities swabbed the inside of Ewing's cheek and entered the results in the national database, Camper said.

District Attorney George Brauchler, whose office is handling the Bennett family case, credited the 2013 Nevada law with the break in the case. Colorado also requires DNA sampling of inmates.

Camper said he hopes the news will allow family members of victims "to heal just a little bit more."

"It's challenging. It's difficult. But we don't forget these cases," Lakewood police Chief Dan McCasky said.

Nevada court records show a jury found Ewing, under the name Alex C. Ewing, was guilty of escaping from the custody of two Arizona deputies at a gas station in Henderson, Nevada, on Aug. 9, 1984. He entered an unlocked home and severely beat a woman and her husband with an ax handle in their bedroom, the records say.

Two young boys were asleep in other rooms.

Ewing, then 23, was arrested two days later by park rangers at Lake Mead.

The Colorado killings followed two other attacks near Denver that authorities suspected involved a hammer.

On Jan. 4, 1984, a couple in Aurora woke up to see a man in their bedroom who hit each of them with a hammer before fleeing. They both survived.

Less than a week later, a flight attendant was beaten, possibly with a hammer, and sexually assaulted after she pulled into the garage of her home in Aurora.

Authorities said those investigations remain active but declined to speculate if they were related to the Smith and Bennett slayings.

Vanessa Burnett, the sole survivor of the Aurora attack, told KUSA-TV on Thursday that she remembers little about it. Now 38, she's scarred, with a metal plate in her forehead. She endured operations, physical therapy and anger issues growing up.

"I was made fun of in school because my parents were killed," she said. "I was made fun of because the hammer man or whatever you want to call it was going to come to my house and hurt everybody when I had slumber parties and stuff."

AP writer Ken Ritter in Las Vegas contributed to this report