The second fugitive was still at large, and Richard McLaren, the jailed leader of the separatist group, issued a call to the man to surrender. Authorities halted the search as darkness fell Monday night, maintaining roadblocks and some key positions to keep the fugitive from leaving the area.
Authorities did not identify the slain fugitive, but they described him as a "middle-aged white male."
The fugitives have been identified as Mike Matson, 48, and Richard Franklin Keyes, 21. Of the two, only Mr. Keyes faced criminal charges - felony warrants for aggravated kidnapping and organized criminal activity. DPS officials said they wanted to talk to Mr. Matson about the siege, but he had not been charged with a crime.
Mr. Matson's brother, Ralph Matson of Colorado Springs, Colo., said Monday night that he believed the dead man was his brother even though officials had not contacted him. "It's my brother. I know that," Ralph Matson said in a telephone interview. "He always said he wouldn't go down without a fight."
In California, Oakland Tribune newspaper officials said Monday night that officials in their city had been notified by Texas authorities that the slain man was Michael Matson. Mr. Matson had lived in Oakland for 13 years.
Authorities said the firefight started about 2 p.m. Monday in the Davis Mountains when the fugitive who was later slain fired at some tracking dogs - one was killed - and a Texas Department Public Safety helicopter.
It was first reported that officers were kept away from the body of the man by shots apparently fired by the other fugitive, but officials said Monday night that they could not be certain that the second fugitive was firing shots or even that he was in the immediate area. DPS spokesman Mike Cox described the shooting scene as "chaotic."
Mr. Keyes and Mr. Matson, both clad in camouflage gear and carrying rifles, had been on the run since Saturday afternoon. Police said they left the compound, a trailer and attached shed that Republic members called their "embassy," rather than surrender to law officers along with the five other Republic members.
Mr. Matson had not faced any charges at the time he left the compound. In an interview with The Dallas Morning News at the beginning of the standoff, Mr. Keyes admitted leading the hostage-taking of two residents of the area, which launched the siege on April 27.
Ralph Matson said his brother had been with Mr. McLaren no longer than 12 weeks when the siege began. The ex-Marine, embittered toward the government since he lost a probate case in California several years ago, hitchhiked to Texas and volunteered to be McLaren's bodyguard after hearing about the group, his brother said.
"My brother was neither a militia man nor a member of the Republic of Texas and never had any interest in the politics of the Republic of Texas," Ralph Matson said. "He went to be a bodyguard for Rick McLaren with the understanding that there would be no surrender."
DPS spokesman Mike Cox said officers allowed Mr. Keyes and Mr. Matson to walk away from the compound Saturday. To confront them, he said, might have jeopardized sensitive negotiations that ultimately resulted in the so-called cease-fire that ended the weeklong siege.
And, the decision looked "smarter and smarter" as searchers discovered the gauntlet of booby traps that would have threatened any pursuers. Officers moving in on the compound after the surrender discovered more than 60 pipe bombs and 12 gasoline cans in the area, as well as several fortified bunkers.
The use of dogs and troopers on horseback in the chase was delayed until officials could clear the area.
The manhunt resumed Monday morning when the dogs - redbone hounds used as trackers by the Texas Department of Criminal Justice - came upon a campsite about a mile southwest of the group's compound. Officials found meal containers that they said suggested the fugitives had been interrupted while eating.
Minutes later, officials said, two hounds were hit by shots from the woods. One was shot in the chest and the other in the leg. Both were taken to a veterinarian.
Then, about 2 p.m., the firefight broke out. Officials said the fugitive who was later shot was in or near a camouflage bunker on a ridge and fired on the tracking dogs, killing one of them.
The man was then shot in the arm by a dog-handler armed with a rifle, Mr. Cox said. The man fell to the ground but got up and began firing at the DPS helicopter, which returned fire. The man was shot again by the dog-handler and killed, Mr. Cox said.
The fugitive's body, which officials said had no identification on it, was airlifted out of the rugged area and taken by ambulance to a Marfa funeral home, where the clothes were removed for evidence. Mr. Cox said the body would be sent to the Bexar County medical examiner's office for an autopsy.
Mr. McLaren, the self-styled ambassador of Republic of Texas faction involved in the standoff, said Monday in a telephone interview with The Dallas Morning News that he was disheartened by the death of a comrade.
"My reaction? Just sadness," Mr. McLaren, 43, said from the Presidio County Jail in Marfa, where he and other members were being held on various charges. "Nobody wanted anybody to die. It's just sad. Really, nobody wanted this."
Mr. McLaren issued a call for the remaining fugitive to surrender peacefully under the terms of a "cease-fire" that broke the standoff Saturday.
"This is Ambassador McLaren with the Republic of Texas," he said. "We're down here in the Marfa jail, and they're taking excellent care of us. I respect the Texas Rangers for what they have done, and they will live up to the deal."
Mr. McLaren said he hopes that the message would be read and then relayed to the remaining fugitive via short-wave radio.
As darkness fell Monday night, DPS officials halted the search but kept up key positions. Mr. Cox said the area was 15 miles from the nearest paved road. He said officials had checked homes in the area and there had been no reports of any stolen vehicles or burglaries.
Republic of Texas members say they believe the state was illegally annexed by the United States in 1845. Mr. McLaren and his followers have split from other factions of the group, which have disavowed his recent activities, which included issuing bogus property liens and financial documents.
Mr. McLaren was being held without bail, sharing a cell with his wife, Evelyn. He and three other jailed members are charged with organized criminal activity; the others were held in lieu of $500,000 bail. Mr. McLaren has vowed to continue seeking independence for Texas; one of the group's demands during the standoff was that the state hold a referendum on independence.
A federal indictment unsealed Monday in Dallas accused both McLarens and five other people of issuing more than $1.8 billion in bogus Republic of Texas financial documents and using them to pay legitimate bills. They were charged with conspiracy, bank fraud, mail fraud and aiding and abetting. Names of the five others were not released because they are not in custody.
If convicted of the federal charges, Mr. McLaren faces a maximum of 725 years in prison and fines totaling $24.25 million. Mrs. McLaren, who appeared before a federal magistrate Monday in Alpine, faces up to 155 years in prison and fines totaling $5.2 million.
She was ordered held without bail until a hearing Friday to decide her bail and whether she will be ordered transferred to Dallas to face the charges. The deal signed by the McLarens and the Texas Rangers specifies that they will be jailed together, but officials said Mr. McLaren would probably remain in Marfa to face his state charges.
Staff writer Scott Parks in Dallas contributed to this report.