By Tim Hull, Courthouse News Service

TUCSON (CN) — Tucson police continue to use traffic stops illegally to check immigration papers and call the Border Patrol, despite a supposed policy against it, the ACLU said in warning letters to police and Homeland Security.

ACLU Arizona Staff Attorney James Lyall sent letters Monday to Tucson Police Chief Chris Magnus and Department of Homeland Security Secretary Jeh Johnson, requesting investigations of the police department's immigration policies and its activities with the Border Patrol.

In reviewing records of 110 police stops between June 2014 and December 2015, the ACLU found 85 incidents in which police prolonged "routine stops far beyond the time reasonably required to resolve the underlying issue, solely to pursue investigations of immigration status or wait for immigration officials to respond," Lyall wrote.

"In many of these cases, officers are going out of their way to transfer custody to U.S. Border Patrol, regardless of the delay that results," he wrote.

Often, legal residents and/or citizens were detained because of false information, Lyall wrote.

"TPD records contained more than a dozen false positives, or 'hits' — instances in which TPD and/or Border Patrol's status check indicated an individual was unlawfully present when in fact the individual either had status (including several U.S. citizens) or Border Patrol declined to take custody for some other reason. In these cases, the false positives were apparently the sole basis for prolonging the stops of individuals who were ultimately released." (Parentheses in original.)

Lyall said these practices go "well beyond" Section 2(B) of Arizona's SB 1070, the so-called "show me your papers" law, which requires police officers to make a "reasonable attempt" to determine an arrestee's immigration status.

They also "reflect fundamental misunderstanding of the Fourth Amendment's prohibition on prolonging stops and limits on the authority of local police to enforce immigration laws," he wrote.

The prolonged stops also violate the Tucson Police Department's own policies, the ACLU said.

The department revised its immigration policies in February 2015 to prohibit officers from delaying release to investigate immigration status.

According to the department's Revised General Order 2335 (pdf): "When reasonable suspicion exists to believe a detainee is unlawfully present in the U.S. but there are no state or local criminal violations, or any other lawful basis to continue the detention (i.e. completion of a traffic stop), the officer shall release the detainee without delay." (Parentheses in original)

The policy also states: "If reasonable suspicion exists to believe a detainee is an unlawfully present person during a valid detention, the officer will attempt to contact ICE/CBP via TPD TWX. If no information concerning the subject is obtained from ICE/CBP by the time that the basis for the detention is concluded, the detainee shall be released without delay."

It adds: "The fact that ICE/CBP cannot verify a person's status does not mean a person is lawfully or unlawfully present in the United States and provides no basis for any enforcement action to include transport or continued detention."

The ACLU review found incidents in which TPD had detained drivers —including at least one mother who was driving her children to school — for more than an hour while checking immigration status and waiting for the Border Patrol to arrive. The stops were generally for minor infractions such as suspended licenses and moving violations, and in many cases the driver should have been cited and released, Lyall wrote.

The letter to Secretary Johnson called for an "immediate investigation of improper U.S. Border Patrol involvement in local law enforcement activities in southern Arizona, specifically Border Patrol responses to routine stops initiated by local police."

Lyall said that many of the records obtained by the ACLU "reveal Border Patrol's continuing disregard for DHS enforcement priorities and contradict the Obama Administration's commitments — issued in response to Arizona's SB 1070 — to limit the involvement of federal immigration officials in traffic stops by Arizona law enforcement, and to protect the civil rights of Arizona residents."

Police Chief Magnus said Monday that he was reviewing the letter.

"I plan to give thoughtful consideration to the issues raised in the letter with an eye toward identifying any opportunities to improve our training, policies, and practices. Information in the ACLU letter will be of value in our evolving efforts to retain and further strengthen a trusting relationship with all members of the community, as we endeavor to fairly enforce the law," Magnus said in an emailed statement. "I look forward to a previously set meeting with ACLU staff and community members next week to discuss our efforts moving forward."

To Learn More:

NYPD Accused of Entrapment and Warrantless Searches at Immigrant-Owned Shops (by Sarah Ryley for ProPublica and the New York Daily News)

The Shady Practice of “Investigatory” Police Stops (by Noel Brinkerhoff and Steve Straehley, AllGov)

Border Patrol Arrests Extend Hundreds of Miles from Border (by Steve Straehley, AllGov)

Little-Known Law Requiring Minimum Number of Immigrant Detainees Leads to Massive Spending Increase (by Noel Brinkerhoff, AllGov)

Immigration Agents Stalk Court Houses to Arrest People When They Pay Traffic Tickets or Get Married (by Noel Brinkerhoff and Danny Biederman, AllGov)

Anti-Illegal Immigrant Criminal Program Shifted Focus Away from Criminals (AllGov)