YELLOWSTONE NATIONAL PARK, Wyo. — An escaped killer with a handgun and a hitchhiking sign expressed relief at his capture on Monday after 10 days on the run, while authorities searched to the north of this tourist-packed 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, Wyo., steps from a church where he sat in a pew a day earlier and sang.

The search for inmate John McCluskey, 45, and Casslyn Welch, 44, focused for a time on Yellowstone National Park, which straddles Wyoming and Montana. But police now believe the two fled the park, with agents following leads in Montana.

“They consider themselves as Bonnie and Clyde,” U.S. Marshal David Gonzales said 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 say 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 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 checkered flannel shirt, and a camouflage backpack slung over one shoulder, worshipper Jay Curtis said. Province looked like the many hitchhikers who pass through.

“Just shook his hand and said ‘Welcome, welcome to our church,’” said Curtis, a member of the church band. “He just smiled and said: ‘Thank you.’“

Province closed his eyes and sang along with the band and seemed particularly engrossed when the band played “Your Grace Is Enough” by Chris Tomlin, Curtis said.

Curtis said that after the service, the pastor paid Province $40 to mow and trim the church lawn.

The town came alive Sunday night with word drifting around that the stranger at the church was a fugitive, Curtis said. “Little bitty Meeteetse they roll the sidewalks up around here at 8:30 at night.”

A woman who had chatted briefly with Province on the steps of the church called police after recognizing him later on television, Gonzales said.

When marshals and other law enforcement officers arrested him, he initially denied being the fugitive, Gonzales said. He was carrying a 9 mm handgun and a sign that said “Casper,” a city to the southeast, police said.

Province remains in the Park County jail and is scheduled for an extradition hearing this morning, authorities said.