HEBER CITY, Utah (AP) - A New Mexico man pleaded guilty Friday to the murders of two hunters in 2001 near the Wyoming-Utah border, and has agreed to testify against his father, who is also charged in the crimes.

Michael David Heffelfinger, 25, pleaded guilty to two counts of aggravated murder and two counts of first-degree felony aggravated robbery in the Oct. 21, 2001, slayings of two Vernal men and the theft of their vehicle.

Heffelfinger's guilty plea spares him the death penalty for the aggravated murder charges.

Heffelfinger also agreed to help the state with their case against his father, Lewis Heffelfinger, 55, who is scheduled for trial in September.

Deer hunters Kelly Jack Carter, 27, and Brad Wesley Gross, 23, were shot multiple times in the hills above Dutch John near Flaming Gorge Reservoir.

Authorities contend the Heffelfingers needed transportation after wrecking their car the day before while they fled from a Daggett County sheriff's officer who intended to cite them for speeding.

In an emotion-filled hearing, family members of Carter and Gross spoke in court, said Nancy Volmer, spokeswoman for Utah district courts. Michael Heffelfinger said he was sorry for the families' loss and hoped they could find some closure, she said.

After Heffelfinger's guilty plea, 4th District Judge Anthony Schofield sentenced Heffelfinger to life in prison without parole for both counts of aggravated murder and five years to life for the aggravated robbery charges.

Events leading to the slayings began the morning of Oct. 20, 2001, when a deputy chased a speeding car but stopped after the car passed two tractor-trailers in a dangerous area.

The next day, an abandoned car and duffel bag were found about 10 miles southwest of where the hunters' bodies later were discovered. Inside the bag were two shotguns, ammunition and a sales receipt, dated days earlier, for one of the guns.

Michael Heffelfinger's name was on the receipt. Lewis Heffelfinger's name was on a warning citation, also found inside, issued by police in New Mexico.

Fellow deer hunter Sage McCormick has testified he found the bodies of his companions after hearing gunshots and saw their truck was missing.

The stolen vehicle was spotted heading south on U.S. Highway 6 near Price, and a chase ensued, which also involved Carbon County sheriff's deputies and Price police. The fugitives fired at sheriff's Sgt. Tom Stefanoff and Kent Allred, a Helper police officer. One bullet struck Allred's car.

The truck was disabled by tire spikes, but the suspects escaped and hid out in the underbrush along the Price River for almost two days. They were found sleeping in a shed southeast of Price.

The Heffelfingers are currently serving one to 15 years for pleading guilty to attempted murder and evasion in the chase in Carbon County.