Two doltish investigators who attempt to see whether Oliver was one of the robbers of the Maylies' home, they are misled by Losborne and sent back to London with misleading information; Losborne makes it seem that Oliver was wounded in a coincident gunshot accident, and that Oliver therefore had nothing to do with the robbery.
The timeline below shows where the character Blathers and Duff appears in Oliver Twist. The colored dots and icons indicate which themes are associated with that appearance.
...robber he once caught named Conkey Chickweed—a story that neither Losborne nor the Maylies can follow—Blathers, with Duff, goes upstairs to talk to Oliver. Losborne and Giles go along as well.... (full context)
...Oliver, the doctor also pulled apart a section of Giles' gun, rendering it useless; thus Blathers and Duff, on examining the broken gun, saw that, whomever Giles believed to have injured... (full context)