Michael S. Donovan sat at the defense table in U.S. District Court in Greenbelt on Thursday preparing to plead guilty to driving under the influence on a federal highway in the kind of case that unfolds dozens of times every day in the courthouse.

Suddenly, Donovan’s plea deal had an audience: a dozen well-dressed Latin American men and women who entered the courtroom and filled two rows of seats. Among them were a judge from Argentina, a public defender from the Dominican Republic, and a chief of staff for a Mexican federal prosecutor.

The legal officials spent half the day at the federal courthouse learning about the American justice system courtesy of the State Department’s International Visitor Leadership program. They were hosted by U.S. District Judge Peter J. Messitte, who has participated in the program for more than 20 years — back to the days when he was a Circuit Court judge in Montgomery County.

The foreign officials learned how cases are filed from Pat Fosbrook, supervisor of the clerk’s office, visited the Marshal’s office, where they got a view of a holding cell, and heard presentations from Stuart Berman, who heads the U.S. Attorney’s office in Greenbelt, and Assistant Public Defender John Chamble, who does the same for the Maryland federal public defender’s office.

The concept of plea bargaining does not exist in the justice systems of most Latin American countries, Messitte said. Berman said more than 90 percent of federal criminal cases end with guilty pleas.