Robert Krentz was found at his ranch on his ATV March 27, shot to death along with his dog, according to reports from the Cochise County Sheriff's office.

Sheriff Larry Dever said that after he was shot Krentz drove away from the scene but soon lost consciousness.

Based on tracks found leading toward the border, law enforcement agents believe that Krentz was killed by an illegal immigrant who may have fled back across the Mexican border.

There was no apparent motive in the murder.

Officials are not optimistic about the chances of catching Krentz's killer.

"As with all law enforcement work it depends on the quality of work we do and a whole lot of dumb luck, frankly," Dever said.

Still, the investigation to find Krentz's killer continues.

"Everybody talks to someone," Dever said. "Our best chance of capturing this guy at this point, with this kind of time elapsed, is that he'll say something to somebody."

The murder has led to renewed interest in border security in the area.

"The general consensus is definitely that we need more border protection," said long-time area resident Ursula Christiansen. "We feel it's the government's job to protect the border."

Christiansen emphasized that it was the responsibility of the federal, and not state government, to provide this security.

Shortly before the murder, Border Patrol arrested eight illegal immigrants and seized almost 300 pounds of marijuana on the Krentz ranch.

"People are more afraid," Christiansen, a friend of Krentz, said. "But at the same time they don't want vigilantism."

People who knew Krentz thought highly of him.

"Rob Krentz was a caretaker – he cared for his family, he cared for the land and he cared for the animals he and his family raised on the Krentz Ranch," the Arizona Cattlemen's Association said in a press release. "The ranching community will certainly miss cattleman Rob Krentz."

Federal and state leaders have joined in the outcry demanding action. Governor Jan Brewer reiterated her request for the federal government to send National Guardsmen to the area.

"For over a year I have demanded that the federal government fulfill my request, joined by the Governors of Texas, New Mexico, and California, to uphold its constitutional responsibilities and increase security along the border through the deployment of additional National Guard troops," Brewer wrote in a statement.

In addition, U.S. Rep. Gabrielle Giffords, D-Tucson, is echoing the call for the federal government to deploy the Guard to the U.S.-Mexico border.

Giffords, who met with Douglas-area residents March 31 to discuss the killing, is advocating horse patrols and better communication among law enforcement.

"This cold-blooded murder is a sober reminder that the safety of U.S. citizens on American soil is under attack,"

Dever, the Cochise County sheriff, knows that all too well.

"We've got kidnappings," Dever said. "We have people who have been taken from here and executed in Mexico.

"It hadn't been so up close and personal until this particular event."