In August, the Denver City Council proposed an ordinance to reduce its cooperation with the Department of Homeland Security to bolster its bona fides as a "sanctuary city." Denver's latest progressive hectoring, prideful virtue signaling, and puerile chest-thumping is icing on the cake.

By whatever delineating characteristics are applied—there is no legal definition—Denver has been a sanctuary city for about 20 years. Soon it will be held accountable for its irresponsible conduct, either by the Trump administration or by a growing legion of crime victims.

Although some Americans harbor wistful fantasies on what it means for a city or county—out of compassion, fairness, or misunderstanding of the Constitution—to declare itself a sanctuary for those illegally in the country, the core issue is whether that government accepts the authority of DHS to enforce federal immigration law. On that, in 2014 DHS placed Denver in the top 10 of jurisdictions that refuse to recognize its authority, putting Denver in violation of at least one federal statute, which makes it a felony to "conceal, harbor, or shield from detection, [an illegal] alien in any place, including any building."

It works like this. When DHS learns a "removable alien" is detained in Denver, it provides officials an " Immigration Detainer – Notice of Action," which advises, "Upon completion of the proceeding or investigation for which the alien was transferred to your custody, DHS intends to resume custody of the alien to complete processing and/or make an admissibility determination." Thus DHS "requests" Denver "notify DHS as early as practicable (at least 48 hours, if possible) before the alien is released," and "[m]aintain custody of the alien for a period NOT TO EXCEED 48 HOURS beyond the time when he/she would otherwise have been released...to allow DHS to assume custody."

In 2014, Denver's response was so egregious (it rejected outright 194 detainer notices) that Obama's DHS began sending Denver forms without the word "detainer," labeled, " Request for Voluntary Notification of Release." In April 2017, the DHS abandoned that pusillanimous approach; meanwhile, however, in February 2017, Denver stopped sending DHS its daily booking sheets.

It was also in February that this bureaucrat battle became flesh and blood.

At 1 a.m. on Feb. 7, 32-year old Tim Cruz was murdered at Sheridan Avenue's light rail station. Days later, his killers were arrested. One was Ever Valles, viewed by DHS as "an immigration enforcement priority" because he is a "citizen of Mexico," entered the United States illegally, and is a "known gang member" with a "criminal history." Thus, in October 2016, when DHS learned of his arrest for car theft, it asked the Denver jail to be told of his pending release.

Nonetheless, on Dec. 20, Valles was released at midnight after Denver sent a fax to DHS just 27 minutes earlier; DHS offices showed the fax arrived at 12:37 a.m. Cruz's family is "livid" over the "senseless" death of a "unique, big-hearted" man. After all, but for the refusal of Denver to hold Valles for DHS, his killer would have been in Mexico. ( Denver did it again in July.)

Denver called the murder "a tragedy," but asserted that, unlike "federal immigration authorities[,]" "[w]e are part of the criminal justice system and do not hold people on civil matters." That odd claim references the ACLU's contention that sheriffs are liable for honoring detainers without proof of probable cause or a judicial warrant.

Unfortunately, Denver has gone further, adopting " policies and practices that protect people's safety and their rights, including the rights of immigrants…." Thus, Denver favors the ACLU's interpretation of the rights of unlawful aliens over the rights of citizens to be protected from the criminal acts of persons fully deportable under federal immigration law. As a result, Denver may have exposed itself to a civil rights lawsuit; after all, it is not just the ACLU that has lawyers.

William Perry Pendley is a contributor to the Washington Examiner's Beltway Confidential blog. He is president of the Mountain States Legal Foundation, has argued cases before the Supreme Court and worked in the Department of the Interior during the Reagan administration. He is the author of "Sagebrush Rebel: Reagan's Battle with Environmental Extremists and Why It Matters Today."

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