HOLDREGE, Neb. (AP) _ Two couples were charged Monday with attempted murder in a shootout that one suspect said ended only when they ''ran out of bullets'' following a helicopter escape from a Colorado prison.

Bond was set was $1 million each for Patricia and Fredrico Gonzales in Phelps County Court. The judge scheduled a preliminary hearing for them for Thursday.

Rebecca and Ralph P. Brown also were charged. The same bond and preliminary date were set for Mrs. Brown, who appeared in court. Brown, who was shot in the hand during the chase and 9-minute shootout Friday, was scheduled to undergo further surgery and appear in court Tuesday, authorities said.

All four were charged with using a firearm to commit a felony and with criminal attempt, which county Deputy Attorney Rebecca Miller described as an attempted murder charge. It carries a maximum penalty of 50 years in prison.

Brown and Gonzales also were each charged with being felons in possession of a firearm, said Dee Berry, deputy county court clerk.

U.S. Attorney Mike Norton in Denver said he planned to file federal charges, probably including air piracy. Colorado officials said they have plans for escape charges.

But Phelps County Attorney Glenn Clark said he has the first right to prosecute.

''We have them,'' he said. ''I don't know what they're (Colorado and federal authorities) going to charge. As long as we have them, they can't get them unless we let them go.''

Brown and Gonzales escaped Friday from the the medium-security Arkansas Valley Correctional Facility in Ordway, Colo.

Prison Superintendent Jim Brittain has launched an investigation into the escape and actions by two prison tower guards who reportedly failed to fire at the helicopter despite radioed orders to do so.

Authorities said the two wives pirated a rented helicopter at gunpoint and forced the pilot to land in the prison yard to pick up their husbands. The women had rented the helicopter on the pretext of looking at real estate.

After picking up the men, the helicopter landed a few miles away and the four transferred to a rental van, leaving the pilot tied up in a shed. He was unhurt.

The four were captured eight hours later after exchanging heavy gunfire with authorities in this south-central Nebraska town of about 5,600, about 400 miles from the prison.

''We ran out of bullets and that's why we finally stopped,'' said Brown, 30.

Mrs. Gonzales, 41, used to work with prison inmates as a volunteer. She met Gonzales, 20 years her junior, at a prison and married him by proxy earlier this year. She was dismissed from her volunteer work for misusing her prison clearance.

Mrs. Brown, 26, interviewed by The Rocky Mountain News in jail Sunday, said she drove the van during the gunfight in Holdrege.

''I don't remember what was going on,'' she said. ''I was just trying to drive the car while under the dashboard, which was about three-fourths of the time,'' she said. ''My husband had been dodging all the buckshots and finally he rolled over to the floor and told me to stop.''

Gonzales was serving a four-year sentence for robbery and would have been eligible for parole in September 1991. Brown was sentenced for sexual assault, theft and criminal impersonation in a bad check charge; his parole eligibility date was October 1996.