U.S. Magistrate Judge Bernardo Velasco’s ruling Friday marked the first conviction against humanitarian aid volunteers in a decade.

The four found guilty of misdemeanors in the recent case were volunteers for No More Deaths, which said in a statement the group had been providing life-saving aid to migrants. The volunteers include Natalie Hoffman, Oona Holcomb, Madeline Huse and Zaachila Orozco-McCormick.

Hoffman was found guilty of operating a vehicle inside Cabeza Prieta National Wildlife Refuge, entering the federally protected area without a permit and leaving water jugs and cans of beans there in August 2017. The others were found guilty of entering without a permit and leaving behind personal property.