Who is Mr. Highgate from Elijah of Buxton and what is their importance?

Theo Highgate is one of the members of the Elgin community. He has a nice home, and although, he is unable to work due to an injury, Highgate attempts to locate the slavers who approached Buxton in the woods. Theo later agrees to accompany the Preacher when he leves to gather Mr. Leroy's family. Unfortunately, the Preacher shoots him and steals the money intended to purchase Mr. Leroy's wife and children. Mr. Highgate survives his wound.