The killing of Arizona rancher Robert Krentz has prompted the state’s governor, its most influential senator, and its farming community to say that Washington is not doing enough to prevent illegal immigration and secure the border with Mexico.

Mr. Krentz was found Saturday, fatally shot and slumped over in his all-terrain vehicle, which still had its lights and engine on. Law enforcement officials tracked footprints from the scene back to the border, raising speculation that the killer is an illegal immigrant.

The apparent murder heightens the tension surrounding the immigration reform debate, with advocates of much stricter immigration controls saying Krentz's death highlights the urgent need for significantly increased border security.

Already, Krentz’s death is being held up as evidence that border violence is spiraling out of control as the Obama administration mulls immigration reform that could include a path to citizenship for some illegal immigrants in the United States.

“It’s scary,” says Dawn Garner, a teacher and yoga instructor whose small ranch abuts the border near Naco, Ariz., just miles from Krentz’s ranch. She says she counts “at least 12” immigrants crossing her property every day.

“It’s become Grand Central Station out here since the Obama administration began talking about comprehensive reform,” says Ms. Garner, whose daughter knows Krentz’s son. “They’re all trying to get up here quickly so they can be inside the country when amnesty – or whatever they want to call it – is announced.”

Calls for action

Since Saturday, Gov. Jan Brewer (R) and Sen. John McCain (R) have called on the Department of Homeland Security to deploy the National Guard to the Arizona border. The Arizona Farm Bureau added: “Until Congress addresses securing the border, all necessary resources should be focused on Arizona's border.”

Authorities have not announced any motive for the killing, nor have they officially suggested that the killer was an illegal immigrant.

For his part, Krentz was well known in the area as a rancher who was kind to illegal immigrants he found on his property, despite having been robbed by them once. “You know, if they come in and ask for water, I'll still give them water," he told PBS's "Religion & Ethics NewsWeekly" in 1999. “You know, that's just my nature."

Krentz’s brother, however, had called border patrol agents the day before the killing. The agents stopped a caravan of illegal immigrants carrying 280 pounds of marijuana, raising the possibility of the crime being retaliation.

An appeal for patience

Experts caution that authorities must understand what happened before conclusions should be drawn.

“An important question to ask is whether the killing of Robert Krentz is more an aberration than the norm at the Arizona border,” says Catherine Wilson, an immigration analyst at Villanova University in Philadelphia. “Did the immigrant responsible for Krentz’s death have ties to the drug-trafficking trade? Will we be seeing more violence at the border due to the heightening of drug-related crime in northern Mexico?”

Advocates for immigrants say Krentz’s death is less an issue of illegal immigration than of the increasing lawlessness in the border areas of Mexico, which affects American citizens and immigrants alike.

“It took the life of a Caucasian rancher, an innocent soul, to garner the attention of the violence on the border,” says Angelica Salas, director of the Coalition for Humane Immigrant Rights of Los Angeles (CHIRLA). “Countless individuals have been murdered at the border during the crossing by ... criminals and their sophisticated networks.”

“Without legal channels for entry into the US, without reform, those who control the border are violent criminals, and the victims are innocent people, including the undocumented, who are raped, injured, and killed,” she adds.