Is it okay for private citizens to shoot unarmed Mexicans trying to cross the US/Mexico border?

Two
people were killed on Sunday night when "an unknown number of subjects
in camouflage clothing armed with rifles" ambushed a truck carrying 20
to 30 undocumented immigrants near the southern Arizona town of Eloy,"
according to the Pima County sheriff's department.

Border
Patrol agents and police found one body in the bed of the pickup truck
and the other nearby in the desert. The identities of the victims have
not been released.

Five other border crossers were found hiding
in nearby brush and were turned over to Border Patrol after being
questioned. The rest managed to escape into the desert on foot.

When
asked if investigators suspect the attack was orchestrated by a
militia, sheriff's department spokesperson Deputy Dawn Barkman said
investigators are "looking into every possibility but nothing is
conclusive."

The truck carrying the immigrants was traveling
in a wash that is commonly used for "human smuggling," according to the
sheriff's department. A wash is a river in the desert that is often
without water.

This is not the first deadly attack by people
reportedly dressed in paramilitary-style gear in the area. In 2007, four
men armed with an assault weapon and wearing camouflage and berets
ambushed a vehicle 40 miles north of Eloy and killed a smuggling suspect
and wounded another person.

The attack comes as the Arizona
legislature is considering a bill that would create a volunteer,
state-sponsored and fully armed militia to aid the Border Patrol along
the United States-Mexico border. Militia members would be able to
pursue, arrest and detain individuals. The 300-person militia would cost
taxpayers $1.4 million annually and would be under the control of the
governor.

Rep. Raul Grijalva (D-Arizona) criticized the bill last month after an appropriations committee approved it.

"This
legislation is not just silly and irresponsible, it's a public safety
threat," Grijalva said. "To arm individuals, provide paper-thin weapons
training and deliberately place them in danger disrespects the taxpayers
of our great state and cheapens the professionalism of our border
security agents."

Crossing the border can be a dangerous task
beyond the threat of attack. Immigrants often die of dehydration or
malnutrition while crossing the harsh Sonoran Desert and attempting to
avoid arrest. The humanitarian aid group No More Deaths has documented 71 deaths of immigrants attempting the cross the Mexico-Arizona border area since October 2011.