The death of a Catholic nun and the serious injury of two elderly nuns in Virginia is more than just a tragedy. It’s the inevitable outcome of the Obama administration’s immigration policy — offering selective amnesty for many illegal aliens while spending tax money on pampering those who break our laws with relative impunity.

Carlos Montano, the drunken driver who crossed the center line and slammed head-on into the nuns’ car, already had two convictions for DUI. He had also been arrested or cited for reckless driving, speeding, and public drunkenness. Officials in Prince William County, Virginia, had previously notified the U.S. Immigrations and Customs Enforcement agency (ICE) at the Department of Homeland Security (DHS) about Montano. But Montano, an illegal alien, was released by ICE on his own recognizance pending deportation proceedings.

An anonymous immigration official at DHS told the Washington Post that Montano’s two prior DUI convictions were not “enough to warrant detention.” That may be the current policy of the Obama administration, but lawyers familiar with the Justice Department’s procedures for immigration and deportation proceedings tell me that is “absolutely not true.” It was common for ICE in the past to detain aliens with two DUI convictions, especially when they had no obvious basis to legalize their status in the United States (such as being married to a U.S. citizen).

And there is no evidence whatsoever in the public record that Montano has any legal basis to remain in the United States. The lawyers told me that aliens like Montano are frequently brought before immigration judges to decide whether the person is a threat to public safety and should be detained. If the immigration judge decides they are not, the judge can still set a bond rather than release the alien on his own recognizance based on the alien’s flight risk.

Montano would have warranted a high bond, and might have had bond denied if DHS had argued to the judge that he should not be released because of the two DUI convictions. Normally, such detainee cases are also brought up very quickly before immigration judges. Yet in this case, DHS apparently didn’t even hold Montano and bring him before an immigration judge when local authorities in Prince William County referred him to DHS.

Instead, ICE simply released Montano on his own recognizance despite the prior convictions. ICE’s requirement that Montano report to ICE on a monthly basis did nothing to keep him from drinking and driving again and killing a nun and seriously injuring two others. On the other hand, if Montano had remained detained in ICE custody until he was ordered removed from the country, he wouldn’t have been out on the streets and could not have harmed anyone.

DHS Secretary Janet Napolitano reportedly ordered an investigation into why “the removal proceedings [were] taking so long.” But that’s the intentionally wrong question designed to shift responsibility form DHS.

The real question: why was this illegal alien released to await removal proceedings instead of being held by ICE and DHS at one of their detention facilities? Answering that question requires no investigation — that is the very policy on the “apprehension, detention, and removal of aliens” instituted by Secretary Napolitano and President Obama.

This policy was formalized in a June 30, 2010, memorandum from ICE Director John Morton to all ICE employees. The priority of ICE, as outlined in the memo, is to remove certain “violent” criminals and essentially to ignore “non-violent” criminals and other illegal aliens. The memo makes no reference to aliens convicted of DUI and other such serious offenses, and there is no statement that such aliens remain a priority.

My sources tell me that this vague memo has created much confusion among ICE law enforcement personnel and will lead to much less focus on enforcement. It abuses “prosecutorial discretion” to order ICE employees to look the other way on most illegal aliens. It may also lead to other problems, such as liberal, activist, federal circuit court judges citing the memo as a basis for not affirming deportation orders against aliens who don’t fit the very limited criteria of “violent” criminals spelled out in the memo.

It essentially gives a de facto administrative amnesty to all other illegal aliens who are caught by ICE or arrested or detained by local and state police officials — including supposedly “non-violent” criminals such as Carlos Montano, whose prior history of DUI, public drunkenness, speeding, and reckless driving would not make him a “priority” for removal under John Morton’s memo. Neither would con men, thieves, burglars, robbers, and all of the other criminals who are supposedly not “violent” enough to warrant the administration’s attention.

With policies like this, it’s not surprising that the ICE employees union has no confidence in Morton’s leadership. Council 118 of the American Federation of Government Employees that represents about 7,000 ICE workers has accused Morton of abandoning the core enforcement mission of ICE to instead implement an amnesty program.