PHILADELPHIA—Two men are being charged in a robbery and gun battle at a north Philadelphia corner store last month that led to slaying of a man who tried to help the store owner.

Police said a masked gunman entered La Familia Latina Grocery Store on March 18 got into a gun battle with the store owner. Both men were wounded, and the robber fled.

Police say 26-year-old Rafael DelValle, who was in the store, pursued the robber and was killed by another man who picked up the assailant's discarded weapon.

Detectives say a 26-year-old man accused of being the robber was being charged with attempted murder, robbery, aggravated assault and related offenses. An 18-year-old man arrested Tuesday was being charged with murder, criminal conspiracy, robbery and related offenses.