William Drum (defendant) was charged with killing David Mohigan. The Commonwealth of Pennsylvania (plaintiff) alleged that Drum and Mohigan had prior disagreements, and Drum armed himself with a dagger with the intention of using it on Mohigan. Drum encountered Mohigan in a saloon, and the two got into another argument. Then, while Mohigan was fighting with someone else in the saloon, Drum allegedly approached Mohigan and stabbed Mohigan on his left side, killing him. However, according to Drum, the knife was his usual hunting knife and he was carrying it because he was preparing for a hunting trip. Drum claimed that Mohigan had been looking for him to "whip him" and was waiting near the saloon for Drum to come out. Drum further alleged that Mohigan eventually went into the saloon and attacked Drum, that Mohigan repeatedly punched Drum, that Drum had no way of escaping from Mohigan, and that Drum pulled out the knife and stabbed Mohigan in self-defense.