Who is Bumpous, and what was his role?

Bobby Bumpous is a paroled convict whom Sheriff Ozzie Walls occasionally relies on as an informant. Ozzie's long-term plan is to "eventually use Bumpous to nail Billy Ray Cobb for dealing," although this is rendered unnecessary after Carl Lee Hailey kills Billy Ray and Pete Willard at the Ford County courthouse. In chapter 2 of A Time to Kill, Ozzie instructs Bumpous to spend time with Cobb at a honky-tonk in order to glean information related to the attack and rape of Tonya Hailey. After two hours inside, Bumpous departs and reveals to Ozzie that Cobb has spoken freely of the crime. He admitted to patrons that "he finally found a nigger who was a virgin. Somebody asked how old she was, and Cobb said eight or nine. Everybody laughed." Bumpous relays Cobb's admission of guilt, as well as his and Willard's position within the crowded bar, enabling the sheriff and his men to easily target and arrest the two criminals after securing a warrant.