Whom did Pip encounter in the graveyard?

In the opening chapter of Dickens's classic novel, Pip is visiting the village cemetery when all of a sudden he is approached by a hostile escaped convict, who threatens to harm him if he does not bring him some food and a file to remove the iron on his leg. Pip is terrified by the convict and reluctantly follows his instructions. Pip proceeds to put food down his leg during dinner and steals some brandy and a pork pie in the morning before returning to the marshes to give the convict his requested items. On his way to meet the first convict, Pip runs into a second convict, who strikes at him before running away. Shortly after feeding the first convict, Pip and Joe follow the authorities on their chase and watch as both convicts are arrested.
Later on, the first convict, whose name is Abel Magwitch, becomes Pip's secret benefactor and gives him money to become a gentleman as restitution for helping him out in the marshes. The second convict was Magwitch's enemy and the primary antagonist in the story, Compeyson.