Editor's note: Ruben Navarrette Jr. is a CNN.com contributor, a nationally syndicated columnist and an NPR commentator.
San Diego (CNN) -- It was a monstrous act, the sort of thing to which even a word like "evil" scarcely does justice.
On May 30, 2009, Shawna Forde and two male accomplices dressed up in camouflage and stormed into the home of Raul Flores and Gina Gonzalez. It happened in the small border town of Arivaca, Arizona, about 60 miles south of Tucson. The intruders were hoping to find a stash of drug money, since they mistakenly assumed the family was trafficking in narcotics.
A native of Everett, Washington, Forde is the founder of Minutemen American Defense, one of those border watch groups that gives vigilantes a bad name, and she wanted money to fund the project. One of Forde's alleged accomplices, Jason Bush, is also part of the group. (Forde was once a member of the Minuteman Civil Defense Corps before being removed from the group for what members described to CNN as unstable behavior.)
Gonzalez has said that her husband woke her and told her that the police were at the door. The woman at the door -- later identified as Forde -- claimed that she and her cohorts were law enforcement officers searching for fugitives. When Raul questioned the story, the three opened fire and killed him. They also shot Gina, but she survived by playing dead.
There were also two daughters. Fortunately, the oldest was spending the night at her grandmother's house. Nine-year-old Brisenia wasn't so lucky. As Gina Gonzalez would later testify in court, Bush fired two shots into the little girl's head despite her pleas. Authorities say it was to get rid of any witnesses.
Gonzalez called 911. The tapes of her hysterically telling the dispatcher that her family had been killed are guaranteed to chill your blood. Within two weeks of the killings, Forde, Bush and Albert Gaxiola were all arrested. Bush confessed, according to law enforcement officials. He and Gaxiola will go on trial for murder this year.
But, for Forde, justice is at hand. It came this week when an Arizona jury convicted her on eight counts, including two counts of first-degree murder, one count of attempted first-degree murder, aggravated assault and robbery.
The only question now is whether the death penalty is justified in this case, something the jury still has to decide. That's an easy one. Of course it's justified. If Forde doesn't deserve the death penalty after committing such a heinous act, then it ought to be stricken from the books, because it has no meaning. She should be executed. And if Bush and Gaxiola are also found guilty, they should be put to death as well.
Regrettably, this story isn't likely to end there. Tragedies like this don't happen in a vacuum. Despite frantic attempts by bigger and better-known Minutemen organizations, in the days after the killings, to disown Forde and portray her as a rogue element, this homegrown domestic terrorist had -- according to media reports -- long been active in the border vigilante movement. That crusade apparently takes all comers; no psychological evaluation necessary. And it generates more than enough ugly racism to stoke people like Forde and her accomplices.
A national group of Hispanic Republicans wants to stop the madness. The organization, Somos Republicans, is demanding that Rep. Peter King, chairman of the House Committee on Homeland Security, hold hearings on acts of domestic terrorism allegedly committed by border vigilantes.
The group also is proposing an Arizona state law that would ban known hate groups and individuals who are tied to known hate groups from roaming and patrolling the U.S.-Mexico border without authorization from authorities.
What happened two years ago on the Arizona-Mexico border was no simple robbery or home invasion. It was a hate crime and an especially brutal one carried out by people who patrol the border with guns and infrared night-scopes because they're convinced the country is being invaded and its culture turned inside-out.
Forde once tried politics. She ran for the Everett City Council on an illegal-immigrant platform, where she complained that Americans would have to speak Spanish to get a job when immigrants outnumber "real Americans."
Presumably, these real Americans include other groups of civilian border watchers, some with neo-Nazi sympathies. Clad in military fatigues, fitted with body armor and carrying assault rifles, these groups prowl the U.S.-Mexico border, trying to keep this country safe from invaders. But who will keep the rest of us safe from them?
Clearly, it's a dangerous situation on the border. Let's not kid ourselves and think that because one group of thugs has been brought to justice, that there aren't others out there ready to do harm. It's not enough to mourn the victims. We have to do everything we can to prevent these tragedies from happening in the first place.
The opinions expressed in this commentary are solely those of Ruben Navarrette.