A few weeks after the 2014 U.S. midterm elections, Secretary of Homeland Security Jeh Johnson announced the creation of the Southern Border and Approaches Campaign and the formation of new task force for sharing intelligence, reducing the flow of illegal immigration and interdicting drugs smuggled across the southwestern border. Spearheaded by Customs and Border Patrol (CBP), Joint Task Force-West (JTF-West) combined personnel from various agencies within the Department of Homeland Security in a multiagency collaborative mission. According to a press release about the campaign:

JTF-West elevates border security from a single CBP effort to a unified DHS partnership that targets organizations that pose the greatest threat.
CBP

Prioritization of the greatest threats would include programs like the "Se Busca Información" ("Seeking Information") initiative, announced on June 16, 2016 by CBP Rio Grand Valley sector in southeastern Texas. This initiative consisted of a tip line enlisting the public's help providing information that might lead to the arrest of the 10 most wanted fugitives in the region.

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The Southern Border and Approaches Campaign also called for increased cooperation with Mexican law enforcement along the shared border. According to the press release:

The new campaign […] positions JTF-West as a key player in relations with Mexico by contributing to discussions between the two governments to improve security on both sides of the border. Topics have included the secure transit of people and cargo and how to bring border communities into the campaign. The strategy 'extends our zone of security outward, ensuring that our physical border is not the first or last line of defense, but one of many,' said [Joint Task Force-West Director Robert L.] Harris

JTF-West extended that zone of security through a cooperative partnership with the state government of Tamaulipas. On June 7, 2018, the Campaign for Security and Prosperity was announced one week after the Mexican Navy special operations forces (UNOPES) was withdrawn from Tamaulipas following complaints to the National Commission for Human Rights (CNDH) about a number (eventually determined to be 47) of forcible disappearances and extrajudicial executions, including of a U.S. citizen. The Campaign for Security and Prosperity expanded the Se Busca Información initiative into a cooperative partnership for sharing intelligence between the U.S. and the state government of Tamaulipas to enhance security and promote mutual interests in business and trade. According to reporting from Olivia P. Tallet at the Houston Chronicle:

…the binational anti-crime collaboration includes the Attorney General’s Office and the Public Security Office from Tamaulipas side, and U.S. agencies from the Department of Homeland Security such as the Air Marine Office, Customs and Border Protection, Homeland Security Investigations, Border Patrol and U.S. Citizenship and Immigration Services, as well as the Department of State, and the Drug Enforcement Agency.

According to a publication from the Tamaulipas government about the Campaign for Security and Prosperity:

As of early June 2018, the state government and seven federal agencies of the United States of America began the collaboration program, the Campaign for Security and Prosperity. This is an unprecedented action in our country through which for the first time is a binational effort against criminal groups that operate on the border of the states of Tamaulipas and Texas.
Ceremony for the announcement of the Campaign for Security and Prosperity Houston Chronicle

In tandem with the Campaign for Security and Prosperity and the Se Busca Información initiative, the U.S. also provided training to the Tamaulipas police. In an October 2017 interview, the Tamaulipas Secretary of Economic Development, Carlos Talancón, described some of the training and assistance the U.S. was providing:

CBP has been training our new state police force in Texas. The U.S. consuls of Nuevo Laredo and Matamoros have visited us in Ciudad Victoria. They have given us equipment, trained dogs. We have been working together with them. They are now training our trainees in Texas. We have been working for the last nine months with them.

In the context of the same interview about U.S. training and assistance, the Secretary of Economic Development in Tamaulipas also described an extermination campaign against the "cockroaches". According to Carlos Talancón:

We are terminating the different leaders. All their soldiers do not have money for gas. They have arms and they are stealing the cars to keep moving. We have a lot of military coming in. About 30 trucks have arrived in Rio Bravo. We are terminating the last cucarachos (cockroaches). They do not have funds, they do not have money, they are just looking around to see where they can get money because they are on their last legs. We are terminating them.

The U.S. has provided training to the Tamaulipas police through both federal and state law enforcement agencies. According to a publication from the Tamaulipas government, between August 2017 and July 2018, the Diplomatic Security Service (DSS), Federal Bureau of Investigation (FBI), Immigration and Customs Enforcement (ICE), Customs and Border Patrol (CBP), Border Patrol (BP) and other federal law enforcement agencies, as well as state and local law enforcement agencies in Texas, provided unspecified training to the Tamaulipas police.

In November 2018, U.S. agents from the FBI, CBP, Texas Department of Public Safety (DPS) and other state and local law enforcement trained personnel from the Tamaulipas state police in Hidalgo county, Texas through the ARSO-I program. The program was reportedly sponsored by the U.S. State Department and included agents from six U.S. security agencies.

According to a press release from the Tamaulipas government from January 2019, members of the Tamaulipas special operations police unit known by their acronym CAIET (Centro de Análisis, Inteligencia y Estudios de Tamaulipas) travelled to Rio Grande City for tactical training with the Starr county special anti-crime unit. According to the Director of CAIET, Felix Arturo Rodriguez:

The idea here is the exchange of ideas, the exchange of tactics, sharing information that both we and they have, and we are seeking the same goal, to prevent crime from increasing and to combat it.

On September 5, 2019, members of CAIET detained 8 people, forced them to dress like sicarios, transported them to the Valles de Anáhuac barrio on the outskirts of Nuevo Laredo and executed them. The police towed a truck to the scene to simulate a vehicular pursuit that never happened and planted weapons on the victims to look like they were killed in a gun fight. One of the victims, Jennifer Romero López, 21, had only been in Nuevo Laredo for 3 days with her boyfriend and was two months pregnant. She had no criminal record.

Days after the executions, the governor of Tamaulipas travelled to Washington and met with members of Congress, officials from the State Department, the Department of Defense and CBP.

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On October 1, 2019, less than one month after the U.S.-trained police executed 8 people, U.S. officials held a ceremony with the governor to announce the re-launching of the Se Busca Información initiative.

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In August 2020, it was reported that the U.S. had also provided training to a new special operations police force in Tamaulipas (GOPES). In October of 2020, U.S. officials from Congress, the State Department and various DHS agencies attended an opening ceremony for a new police facility in Reynosa that the GOPES would use as one of their two bases of operations. Three months later, on January 22, 2021, members of the GOPES and Tamaulipas state police operating out of the new facility in Reynosa killed 19 people, most of them migrants from Guatemala.

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On February 7, Jorge Monroy reported in El Economista that the United States Embassy in Mexico acknowledged that three of the GOPES charged with the 19 murders were vetted and trained in human rights by the U.S. in 2016 and 2017 prior to joining the GOPES.