Our last post talked about the terrifying situation in which one man found himself. Juan drove into the United States everyday for school, and he worked hard to keep himself and his family safe. However, one day when he was driving across the border, he was stopped, and his car was searched.

The border patrol found 50 pounds of marijuana in the man's trunk. Although Juan insisted that he knew nothing about the drugs, he was arrested and convicted. His attorney filed an appeal almost immediately.

After spending time in prison, Juan was released. The judge dismissed the case against Juan. But why?

In the months following Juan's arrest and conviction, the judge who heard Juan's case also heard several others that had striking similarities. It was enough to catch the judge's attention, so he notified the FBI.

An investigation revealed what Juan already knew: the drugs had been planted in his car.

In order to pass through the border quickly, Juan had applied for a SENTRI pass. The pass allows individuals to pass through the border with minimal inspection. In order to qualify for a SENTRI pass, individuals must have clean backgrounds, and they must pass rigorous interviews. Unfortunately, once they do that, they become a target for the Mexican drug cartel.

The drug cartel hired people to monitor the SENTRI lane, and they recorded the make, model and color of the cars of people who had consistent routines -- mostly students and professionals. Members of the drug cartel would then follow the car of their target into Mexico, record its VIN and attach a GPS tracking device to the car.

From there, the VIN was used to make two copies of the car's keys. One set of the keys was given to a member of the drug cartel in Mexico. That person used the keys and information from the tracking device to plant the drugs in the trunk of the person's car. Once the unsuspecting target drove into the United States, a member of the drug cartel would use the second set of keys with information from the GPS to retrieve the drugs.

It was a simple but effective plan -- until one judge noticed the similarities in several drug convictions. Each person who was caught with drugs was driving a Ford. Each person had two black duffle bags, each of which were loaded with 50 pounds of marijuana, and the bags were attached to each other with slip ties. Finally, everyone who was convicted denied having any knowledge of the drugs, though none of the locks on their cars had been tampered with.

Although the people who were wrongly convicted were freed, the judge cannot return their lives to normal. The people cannot get time back for the months spent in prison. And a judge certainly can't help them evade the uneasy feelings that come with being followed, tracked and used as a pawn for the drug cartel.

Source: CNN, "'Blind mules' unknowingly ferry drugs across the U.S.-Mexico border," Emily Smith, Jan. 24, 2012