Cops look at border vigilantes in migrant murders

TUCSON -- From today's Chicago Tribune story, U.S. border clampdown has violent side effects.

"Because three of the gunmen were white men and the other a Hispanic man with limited Spanish, authorities are looking at the prospect of vigilantism, according to Pena and Pinal County Sheriff's spokesman Mike Minter."

Pena is the U.S. Immigration and Customs Enforcement's special agent in charge of Arizona.