A West Virginia man has pleaded guilty to retaliating against a government witness in a criminal case involving the man’s brother.

David Stanley admitted Monday in federal court that he sent several intimidating and threatening messages through social media to a witness in a case against Stanley’s brother.

David Stanley faces up to 20 years in prison and a $250,000 fine when he is sentenced Sept. 8.

His brother, Charles Stanley, pleaded guilty in February to charges related to the theft of mining equipment from an energy facility.