American officials arrested a former U.S. Marine on Thursday for allegedly taking part in a raid on North Korea's embassy in Madrid earlier this year, sources told Reuters. Christopher Ahn is expected to be arraigned in a Los Angeles court on Friday for allegedly being a member of a group—called Cheolima Civil Defense—that sought to overthrow of North Korean leader Kim Jong Un. During the April raid, the group stole electronics and hard drives from the embassy and came to the U.S.—where they reportedly passed along information to the FBI. Sources told Reuters the material was returned to the embassy by Spanish authorities. In addition to stealing materials, the group of at least 10 beat embassy employees and held them hostage. According to a Spanish court, one of the members encouraged an embassy employee to defect from North Korea during the raid. The court believes some of the group's leaders are in the U.S., and are seeking their extradition. The Justice Department reportedly declined to comment.