Police say four days after the fatal shooting they arrested 25-year-old Kaheef Edwards and charged him with murder and theft.
Twenty-year-old Rasheed Tancemore is still being sought by police in connection to the crime.
A $20,000 reward is being offered for tips leading to the arrest and conviction of Tancemore of West Wishart Street in Philadelphia.
Police believe Edwards and Tancemore shot and killed 20-year-old Donald Green during a robbery back on Jan. 27.
It happened as Green and a 19-year-old friend were leaving Edwards Grocery on Neilson Street at Hunting Park Avenue.
Tancemore is described as armed and dangerous.
Anonymous tips concerning his whereabouts can be submitted by calling 215-686-TIPS.