It happened after 10:00 p.m. Thursday at Rite Aid at the intersection of 9th and Highland.
The two suspects were caught on surveillance: a woman wearing a red hoodie with white stripes down the sleeves, blue jeans and gray sneakers; and a man wearing a white V-neck shirt over a black long-sleeve top, rolled up blue jeans and black boots.
They are wanted for the murder of the store's manager - identified by family as 40-year-old Jason Scott McClay of Broomall, Delaware County.
"He said it was dangerous - all the time," said Bruce McClay, victim's father.
McClay's father, Bruce, came to the store at 9th and Highland streets on Friday morning.
He said his son wasn't supposed to work the late shift last night- and didn't want to - he wanted to watch the Eagles game instead.
"He was filling in for somebody. Somebody was coming in I believe from Harrisburg- another co-worker but she couldn't make it on time," said Bruce.
Police say as the store was closing for the night, the two suspects came in and got into a confrontation with McClay.
"We believe it was in the commission of a robbery it occurred," said Chief Joseph Bail, Chester Police.
One of the suspects shot McClay in the head. He was pronounced dead when police arrived.
On Friday, Rite Aid offered grief counseling for employees and issued a statement on the murder.
The statement read in part:
Today we are grieving the loss of a member of our Rite Aid family who was tragically killed last night in this location. We're working closely with authorities regarding this matter
Security guards were at the store Friday, but no one was on duty at the time of the incident Thursday.
Bruce said his son had asked his corporate bosses to provide more security.
"It seems to me that it's a decision that's a money decision - that they don't put somebody here because it costs money - but now they probably will, but it's cost somebody their life now," said Bruce.
Family members say McClay had only worked at the store for about a year.
The Rite Aid Corporation with Purdue Pharma conjunction with the Citizens Crime Commission is offering a $20,000 reward for information that leads to an arrest and conviction. Information can be called in to the Crime Commission Tipline at 215-546-TIPS (8477). You don't have to give your name.
Information can also be called into Chester Police at 610-447-8431, Delaware County Criminal Investigations Division Detective Dave Tyler at 610-891-4708 or 911.