United States Border Patrol Agents were angered after they provided armed security at a wedding for a convicted drug smuggler during a rare opening of the steel gate on the U.S.- Mexico Border fence in November.

The wedding took place during a “Door of Hope” event which provides families the opportunity to be reunited for a few minutes at the fence in Border Field State Park.

For the wedding, Brian Houston, a U.S. citizen who is awaiting sentencing in San Diego federal court on a drug smuggling conviction, met his fiancé at the steel gate on the U.S.-Mexico Border, the San Diego Tribune reported.

The wedding came as a surprise to the U.S. Border Patrol agents assigned to the opening of the gates, who closely watch the interactions between those involved in the rare event. The encounters are held in a small strip of land owned by the Department of Homeland Security known as Friendship Park and only vetted families are allowed to take part in the event. For a short period of time, the gates are opened.

The criminal complaint filed in the case against Houston revealed that federal authorities arrested him in February as he crossed through the San Ysidro Port of Entry after they found multiple drug packages in his vehicle. At the time, officers seized 43 pounds of heroin, 47 pounds of methamphetamine, and 43 pounds of cocaine.

“The agents are upset, feel like they were taken advantage of, feel like they were duped,” Joshua Wilson, vice president, and spokesman for the National Border Patrol Council Local 1613 is quoted by the Tribune. “Turns out we provided armed security for a cartel wedding.”

The event was is put together by Border Angels, a nonprofit group who was able to get authorities to assist in opening the gates. For the event, the group has families who are not able to cross the border fill out questionnaires which are then turned over to the U.S. Border Patrol. Federal agents go over the forms and vet the families that are able to take part in the event. It remains unclear how Houston’s conviction went unnoticed.

Robert Arce is a retired Phoenix Police detective with extensive experience working Mexican organized crime and street gangs. Arce has worked in the Balkans, Iraq, Haiti, and recently completed a three-year assignment in Monterrey, Mexico, working out of the Consulate for the United States Department of State, International Narcotics and Law Enforcement Program, where he was the Regional Program Manager for Northeast Mexico (Coahuila, Tamaulipas, Nuevo Leon, Durango, San Luis Potosi, Zacatecas.)