TIJUANA, Mexico—You know you’ve screwed up when even Mexico’s notorious drug cartels think you’ve gone too far.

That’s what happened to a couple of alleged thieves who are accused of killing a trio of foreign tourists—including an American—who were found dead in Baja California this weekend.

U.S. national Jack Carter Rhoad and Australian brothers Callum and Jake Robinson were reported as missing on April 27 after taking a surfing trip near the city of Ensenada. On Monday Baja California state authorities confirmed the lifeless bodies of the three tourists were found at the bottom of a cliff and detailed the cause of death: each had received a shot to the head.

Ensenada is currently under control of a Sinaloa Cartel faction headed by the Arzate brothers, René and Aquiles, according to Mexican authorities.

A member of this criminal organization who spoke with The Daily Beast on the condition of anonymity said the robbers involved in the killing were not part of a cartel.

“They were low-level robbers acting alone. But we handed them over,” he said. “We learned that the cops were looking for the gringos and also began looking for those who were responsible. We called the authorities to let them know where to find them.”

The cartel member said that the criminal organization was afraid of getting “unwanted attention” from Mexican authorities.

Baja California investigators told The Daily Beast that the three tourists were killed after trying to de-escalate a confrontation with robbers who wanted to steal the pick-up truck they were driving.

Guillermo Arias/AFP via Getty Images

The three men were leaving a remote area south of Ensenada where they had camped a night before and heading towards an Airbnb they had rented for that night. As they were departing the area a group of men showed up to talk to them and at some point of the conversation they demanded the pick-up truck they were driving.

“The tourists refused and tried to fight back, but the robbers were armed. When the criminals took out their guns the three [tourists] tried to de-escalate things, but it was too late, they beat the three of them and then shot them in the head,” the investigator said.

The attackers then burnt the tents and some of the tourists' belongings attempting to get rid of any evidence that could lead to them, said the investigator.

Investigators got in touch with U.S. authorities in San Diego and obtained the phone numbers of the cellphones the tourists were using at the moment.

“We tracked down the devices, until one of them was turned on and we had a location. That’s when we found this woman who was in possession of the American’s cellphone,” the investigator said.

The pick-up truck was later found at a different location further north Ensenada at a private ranch. The vehicle had also been burned in an attempt to erase evidence of the crime, investigators said.

Authorities first announced the arrest of three suspects related to the killings, but in a confusing press release published on Tuesday they said they only had arrested the woman.

Investigators also said the body of another man was found along with the tourists, but they believe this was unrelated .“The other body found among the three men had been there for a longer period of time, suggesting this is not related to the case of the three tourists,” the investigator said.

On Monday relatives of the trio traveled to Baja California to identify the bodies.

In a Facebook post, Debra Robinson, the mother of the two Australians, said the group had been due to check into an Airbnb in Rosarito after a camping weekend but “they did not show up.”

Speaking to 7News, Robinson said 33-year-old Callum and 30-year-old Jake, from Perth, had attended Coachella a week before crossing the border into Mexico. Callum, a member of Australia’s national lacrosse team, lives in San Diego. Jake had left Australia two weeks ago to join his brother for what their parents called the “trip of a lifetime.”