The father and son team of security guards was at its usual post guarding an explosives magazine in Durango, northern Mexico, when the assailants arrived.
Two white Suburban-type SUV’s rolled up and 15 to 20 masked men stepped out bearing automatic rifles.
“The security guards were ordered at gunpoint to open the magazine, and the gunmen made off with a large quantity of Tovex brand explosives and electric detonators,” reads a report by the United States Bomb Data Center obtained by GlobalPost.
The theft was in February 2009 on a site owned by a Texan company in Mexico.
On July 15 this year, the same type of explosives went off in a car in Ciudad Juarez, killing a federal police officer, doctor and civilian.
While car bombs have long been used in Iraq and Colombia, this was the first effective use of such a weapon against police in Mexico.
It sent waves of fear across Juarez and the nation, because car bombs have a terrifying potential to hit civilians not involved in the drug wars.
Mexican police confirmed last week that Tovex explosives were set off by a mobile phone-operated detonator, and said the explosives were likely stolen from a U.S. company.
If it was from the same magazine raided in Durango, it would implicate the gangsters have plenty more of the material.
The report states that 267.75 pounds or 900 cartridges of the explosives as well as 230 electric detonators were taken. That attack used just 22 pounds to make the bomb.
Stoking these fears, gangsters sprayed graffiti on the walls of Juarez, promising more such attacks.
“We still have car bombs,” said one message in black spray paint.
The report said the assailants threatened the guards and their families over the incident.
“The leader of the armed group took the guards’ address and threatened to return to kill the guard and his family if they reported the crime during the 30 minutes it would take the group to flee. The group initially intended to take the father with them but did not do so after he determined the guard did not know how to use explosives,” it said.
The report also warned back last year that the theft could lead to bomb attacks.
“This incident has the potential to lead to further explosives-related incidents in the region, especially if the armed subjects are connected to a Drug Trafficking Organization,” it said.
In Ciudad Juarez, 250 soldiers scoured the city for explosive material.
The troops used British-made molecular-seeking devices that can detect explosives. However, they had located no bomb-making material by Thursday.
American agents from the Drug Enforcement Administration and the Bureau of Alcohol, Tobacco, Firearms and Explosives were also in Juarez aiding Mexican officials with the investigation.
“This bomb shows how the conflict in Mexico is escalating,” said an American law enforcement official involved in the struggle against cartels. “The gangsters are fighting police and soldiers with body armor. So they have started using bombs to hit them. But bombs do not discriminate and they often harm civilians.”
The explosives were set off using a ruthless trap.
First, the gangsters kidnapped a civilian, dressed him in police uniform, shot him and then dumped his body. When the federal police came close they set off the car bomb.
“Such an attack has implications for anyone attending crime scenes, including police, paramedics and journalists,” the official said. “They have to think about the possibility they are being lured into an IED.”
Mexican police blamed the attack on La Linea, a gang of assassins who work for the Juarez drug-smuggling cartel.
They say it was in retaliation for the arrest of alleged La Linea commander Jesus Acosta, a.k.a. El 35.
Federal police had released an interrogation video in which Acosta confessed to working as a cartel hit man.
It was the latest of several videos of captured cartel members describing how they allegedly set up murders and carved limbs and heads off victims.
Critics accuse the police of obtaining the videos through torture and say they fail to provide clear evidence while provoking gangsters to retaliate.
Graffiti apparently sprayed by the La Linea accused the federal police of working with their arch rivals the Sinaloa Cartel, of Mexico’s most notorious mobster Joaquin “Chapo” Guzman.
One message addressed American officials, demanding they investigate the corruption.
“FBI and DEA. Go and investigate authorities that are giving support to the Sinaloa Cartel,” said the message on the wall of an elementary school. “If not, we will put more car bombs.”