MONTE ALTO, Texas (AP) — An American missionary couple who were attacked by gunmen in Mexico drove up to an illegal roadblock in a dangerous area of the country that has had 40 violent car thefts in the last two months, a Mexican official said Thursday.

The gunmen opened fire after the driver, Sam Davis, decided not to stop, said an official in Mexico’s Tamaulipas state attorney general’s office who would not be identified because he is not authorized to discuss the case.

Davis’ wife, Nancy, was shot in the head by a bullet that shattered the rear window of their 2008 Chevrolet pickup truck, Pharr police Chief Ruben Villescas said Thursday.

Sam Davis told U.S. investigators that he drove as fast as he could to the border, about 70 miles away, with his wife bleeding in the seat next to him. Faced with a long line of traffic waiting to enter the U.S., he drove in the opposite lane across the Pharr International Bridge to the border checkpoint.

Nancy Davis, 59, was rushed to a hospital in McAllen, where she was later pronounced dead. An autopsy was scheduled for Thursday.

Authorities say the couple’s heavy-duty truck is the kind prized by criminal organizations in Mexico, and similar to ones Pharr police say they can often single out as stolen before the vehicles are driven across the border.

"Driving that type of truck is an eye-catcher," said Pharr police Sgt. Ray Lara, who routinely patrols bridge traffic. "We figure maybe they don’t bother the church people. But they want those trucks."

There were conflicting reports about where the attack occurred. In a news release on Wednesday, the Pharr Police Department said it happened near the city of San Fernando, about 70 miles south of the Mexican border city of Reynosa. That area is controlled by the Zetas drug cartel, which was blamed for the massacre of 72 Central and South American migrants found slain in August.

But according to the Tamaulipas official, the assault happened about 7 miles south of Reynosa on a highway connecting San Fernando with the border. The area is one of Mexico’s most violent and dangerous, and is controlled by the Gulf Cartel, and has seen a spate of recent violent car thefts, the official said.

Pharr police chief Ruben Villescas said he planned to speak with Mexican investigators on Thursday. He declined to say where Sam Davis was on Thursday or to give details about Davis’ church, citing the need to protect Davis.

The couple’s son, Joseph Davis, told The Associated Press on Thursday that his parents knew the risk of working in certain parts of Mexico, but that they were devoted to their missionary work. He said his parents had been chased by gunmen before, and that his mother would often text message him to let him know when they had crossed safely back into the U.S.

"It would be easier" to count the number of times they weren’t targeted during recent trips to Mexico, Joseph Davis said at his Monte Alto home. His parents began their missionary work in Mexico in the 1970s.

Nancy Davis’ slaying echoes the suspected slaying in September of American tourist David Hartley, who was gunned down by Mexican pirates while Jet-Skiing on a border lake, according to his wife. His body was not recovered. 

"I don’t know them, but my heart breaks for them," Tiffany Hartley said of the Davises.

After the Hartley attack, Texas Gov. Rick Perry called for a stronger response from Mexican authorities to bring those responsible to justice. On Thursday, Perry’s spokeswoman, Katherine Cesinger, said Nancy Davis’ slaying underscores the need for greater border security.

"How many Americans are going to have to die for the federal government to pay attention and realize they need to secure the border," she said.

Merton Rundell III, a friend of the Davis’ and the director of finance at Union Bible College in Indiana, said the Davises spent 80 to 90 percent of their time in Mexico and had a home in the Mexican state of Nuevo Leon. He said they spent the rest of their time in Texas or traveling the U.S. raising funds for Gospel Proclaimers Missionary Association, the organization they founded.

"They’ve been working in Mexico for over 30 years. It was mainly establishing churches — that was their main thrust.

"They loved the work they were doing in spite of the danger," Rundell said. 

Rundell described Nancy Davis as "a petite lady with a drive like you wouldn’t believe. She lived life to the fullest. They were both totally given to (their work)."


Associated Press writers Terry Wallace and Linda Stewart Ball in Dallas, and Katherine Corcoran in Mexico City contributed to this report.