A team of masked cartel hitmen attacked an auto body shop in the Mexican border city of San Luis Rio Colorado, Sonora, and killed three suspected Sinaloa Cartel operatives. The Saturday night attack also left another man seriously wounded. Investigators discovered a weapons cache featuring a rocket-propelled grenade launcher at the scene.

Police in San Luis Rio Colorado are investigating the presumed cartel attack on the shop a short distance from the international border crossing into Arizona, according to local reports. Officials presume the hit team stormed the business and immediately opened fire–killing two with a third dying at a local hospital. A fourth victim sustained severe gunshot wounds and is receiving medical care.

During the ensuing investigation, police discovered two AK-47s, four pistols, an RPG (rocket-propelled grenade launcher), four radios, tactical equipment, $96,000 pesos (nearly $5,000 USD), and methamphetamine, according to the Sonora state attorney general’s office. The cartel hitmen reportedly arrived in a dark sedan and left .223 caliber shell casings scattered at the scene. Investigators also located two stolen vehicles inside the shop; one was reported taken in San Diego, California, and the second from Yuma, Arizona.

According to local media reports and Breitbart Texas law enforcement sources, the victims allegedly were operatives for a cell of the Sinaloa Cartel known as “Los Salazar.” Authorities identified the three deceased as Alberto Félix Castro, 29; Ricardo Humberto Borboa Villalobos, 33; and Guillermo Saavedra “El Chester” Burboa, 34. Investigators identified El Chester as a high-ranking regional member of Los Salazar. Sources say the attack is likely the result of Sinaloa Cartel infighting.

In September, a key Sinaloa Cartel operative was gunned down on the outskirts of a rural community in Valle de Mexicali near Arizona. Police identified one of the victims as Julio César Aguilar García, aka “El Vaquero,” a key regional member linked to Ismael Zambada García “El Mayo,” the leader of the Sinaloa Cartel. A second victim was Rodolfo Antonio Galindo, aka “El Chupacabra.”

Robert Arce is a retired Phoenix Police detective with extensive experience working Mexican organized crime and street gangs. Arce completed work assignments in the Balkans, Iraq, Haiti, and recently completed a three-year tour in Monterrey, Mexico, for the U.S. Department of State, International Narcotics and Law Enforcement Program.