Police allege that the victim was arguing with the older man Saturday afternoon outside the Lawrenceville store.
Lt. Dan Herrmann told the Pittsburgh Post-Gazette ( http://bit.ly/SCoVpE) that the younger man shot 46-year-old Gary Hager of Ross Township shortly before 4 p.m. Saturday.
Police said Hager was able to run into the store for help before collapsing. He was pronounced dead at UPMC Mercy minutes later.
Fifty-two-year-old Darrell Tigney and 24-year-old Maurice Tigney were charged with criminal homicide and conspiracy.
Listed numbers for them could not be found Sunday and it was unclear whether they had attorneys.
Information from: Pittsburgh Post-Gazette, http://www.post-gazette.com