How can we legally fire the union shop steward?

Q. Recently, we did an exhaustive investigation to determine who damaged a piece of company property. Several people had access to the property, but the investigation narrowed down to one person. Everyone else, except this person, had witnesses to corroborate their statements that they didn’t damage the property. When interviewed, the person in question changed his story on three separate occasions. The company has decided to terminate this employee. He is the shop steward for the union, so it's likely to get ugly. What are your thoughts? – Supervisor, West Virginia