"Homeland Security Secretary Janet Napolitano has ordered an investigation after a man who was in the United States illegally killed a nun in a car crash, authorities said.

Napolitano is trying determine why the man was still in the country because he had been arrested two previous times for drunken driving offenses.

The suspect, Carlos Montano, driving Sunday morning under the influence of alcohol, slammed head-on into three nuns in a Toyota sedan, police said. The three were just a few miles from a monastery in Bristow, Virginia, heading for their annual retreat. Sister Denise Mosier was killed instantly, and the other two remained hospitalized Tuesday.

The suspect has twice been in custody -- the first time, almost two years ago in October 2008 -- Immigration and Customs Enforcement officials said. But both times, Montano was released on his own recognizance pending deportation proceedings, because he was not convicted of a violent felony such as murder, rape, or robbery." -Dugald McConnell and Brian Todd, CNN

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