On Saturday, October 24th of this year, a Customs and Border Patrol officer at the US-Mexico border crossing that separates Nogales, Arizona from Nogales, Mexico noticed that a Mexican man headed into the United States was behaving suspiciously. He ordered the man to pull his car over for a secondary inspection and officers subsequently found 44 pounds of marijuana inside a hidden compartment in the vehicle's trunk. However, instead of placing the driver in a US jail, he was instead handed over to Mexican authorities for trial in his home country.

The driver, 27-year-old Eleazar Gonzalez-Sanchez was no doubt shocked when US law enforcers handed him over to his own country's federal prosecutor's office, the Procuraduría General de la República, or PGR. That is because he is the first person to be prosecuted pursuant to the so-called Controlled Substance Project, a ground-breaking pilot program involving the PGR, US Customs and Border Patrol, and US Immigration and Customs Enforcement. The Controlled Substance Project, which at this time involves only the Nogales border crossing, enables the PGR to prosecute – under Mexican law – Mexico's drug smugglers who are nabbed by US authorities.

"This agreement represents the commitment that U.S. and Mexican law enforcement agencies have in working together to find ways to stem the flow of narcotics across the border," said Matt Allen, special agent in charge of the ICE Office of Investigations in Arizona. "Both nations recognize the violence and the corrupting influence that the illicit drug trade brings to our communities."

The Gonzalez-Sanchez case illustrates how the Controlled Substance Project works. After the CBP officers discovered the marijuana in his car, ICE agents responded to the scene and initiated a criminal investigation into the smuggling attempt. After consulting with the US Attorney's Office in Tucson, ICE agents contacted the PGR to inform Mexican prosecutors of the case. PGR attorneys examined the evidence and accepted prosecution. ICE and CBP released Gonzalez, his personal effects and core samples of the marijuana to the PGR. All of this took place on a single day.

Two days after the incident, a federal judge in Mexico found probable cause to proceed with the case. Mexican prosecutors said that to the best of their knowledge, it was the first-ever drug smuggling prosecution based on a criminal complaint from a foreign law enforcement agency.

During an interview, Vincent Picard, a spokesman for ICE's Phoenix office, said the Controlled Substance Project is the product of ongoing communication between DHS component agencies and the PGR, which "have had a positive relationship for some time". He explained that all parties involved have an "inherent interest" in stopping the flow of drugs across the border and that during various conversations about how to achieve that goal, "this idea was broached".

Picard added that CBP, ICE and the PGR signed the formal agreement in September. When asked whether there are plans to expand the Project to other US-Mexico border crossings, Picard said no decision has been made at this time.

"At this point things are going very well. We have one successful referral for prosecution under our belt and we're going to see where it goes from there. We are going to look to see if its something we can expand," Picard said.

Brett Wolf, an  HSToday.us correspondent, is an anti-money laundering analyst with Complinet, a London-based firm that helps financial institutions meet their compliance obligations. He has been writing about financial crime for more than a decade and holds an anti-money laundering certification from the Florida International Bankers Association and Florida International University