An escaped killer with a handgun and a hitchhiking sign expressed relief at his capture after 10 days on the run, while US authorities searched to the north of the Yellowstone National Park for a second fugitive and his female accomplice, a self-styled "Bonnie and Clyde".
Tracy Province, 42, was caught as he walked in sleepy Meeteetse, Wyoming, steps from a church where he sat in the pews a day earlier and sang "Your Grace Is Enough".
The search for inmate John McCluskey, 45, and Casslyn Welch, 44, focused for a time on the sprawling park, which straddles Wyoming and Montana.
But authorities now believe the two fled the park with agents following leads in Montana.
"They consider themselves as Bonnie and Clyde," US Marshal David Gonzales said at a news conference in Phoenix. "This is very, very serious business."
Province, McCluskey and Daniel Renwick escaped from a private, medium-security Arizona State Prison near Kingman on July 30 after authorities said Welch threw wire cutters over the perimeter fence.
Welch is McCluskey's fiancee and cousin. Renwick, who turns 37 on Tuesday, was captured in Colorado.
Efforts to find the remaining three intensified after they were linked to a double homicide in New Mexico, with the case airing on Saturday on America's Most Wanted.
On Sunday, Province walked into Meeteetse Community Church, about 60 miles outside of Yellowstone, wearing blue jeans, a blue flannel shirt, and a camouflage backpack slung over one shoulder, worshipper Jay Curtis said. Province looked like the many hitchhikers who pass through town.
"Just shook his hand and said 'Welcome, welcome to our church'," said Mr Curtis, a member of the church band. "He just smiled and said: 'Thank you'."
A woman who chatted briefly with Province on the steps of the church called police after recognising him later on television, Mr Gonzales said.
When marshals and other law enforcement officers arrested him, he initially denied being the fugitive, Mr Gonzales said. He was carrying a 9mm handgun and the sign that said Casper, a city about 160 miles to the southeast, authorities said.
Province was in the Park County jail and scheduled for an extradition hearing, authorities said.
Gonzales said a 40,000 US dollar reward was set for McCluskey and Welch's capture.
The Arizona Attorney General's Office charged two women, including McCluskey's mother, with helping the inmates after they escaped.
Province was serving a life sentence for murder and robbery. McCluskey was serving a 15-year prison term for attempted second-degree murder, aggravated assault and discharge of a firearm.
Forensic evidence linked the two inmates and Welch to the killings of an Oklahoma couple. New Mexico State Police spokesman Peter Olson declined to elaborate.
The badly burned skeletal remains of Linda and Gary Haas - both 61 and from Tecumseh, Oklahoma - were found in a charred camper van on Wednesday morning on a remote ranch in eastern New Mexico.
Their pickup truck was found later 100 miles west in Albuquerque.