The suspect's mother says her son is not the shooter.
"Do I believe my son had a gun? No, no, I don't," said Renita Carter.
Carter says her son was not responsible for the shootings.
"One individual was shot. He is deceased. There was a gun recovered at the scene," said Mark Payne, Police Independent Review.
Winston's mother showed up at the scene shortly afterward and says she heard other suspects were involved and calls her son a victim.
"The police heard the gunshot, so they started (after), I guess, the ones that were running because the guys that w(ere) shooting at them were in a car. So instead, (of) you chas(ing) the ones that w(ere) shooting at them, you chase the ones on feet," Carter said.
Officials say two 29-year-old men were in critical condition at Christ Hospital in Oak Lawn, a 67-year-old woman is in serious condition at Stroger and a 16-year-old girl outside the store suffered a graze wound.
A Chicago police spokesperson said there was confusion on the scene and many people running, but there is only one suspect. The spokesperson says that Winston is the only official offender, but they are still investigating.
Emergency crews responded at 6:57 p.m. to a shooting at East 71st Street and South Paxton Avenue, Fire Media Affairs spokesman Joe Roccasalva said. The shooting reportedly happened at the Best Buy Meats & Groceries.
A Grand Crossing District police squad car in the area heard shots fired and was first to the scene. The officers initially did not know anybody was wounded at the store and began chasing a man they saw running from the scene with a .357 revolver, according to law enforcement.
Other responding officers reportedly discovered three gunshot victims -- two inside the store and a woman shot in the ankle a short distance away. A teenager later walked into a South Side hospital suffering from a graze wound in the grocery shooting, police said.
The officers first on the scene continued the chase and followed Winston into an alley in the 7100-block of South Merrill Avenue, where they reportedly ordered him to drop the weapon.
Instead, Winston allegedly turned around and pointed the revolver at the officers, who were still in the squad car. The officers then reportedly fired shots, striking him.
Chicago Fire Department ambulances took the three survivors to area hospitals following the shooting, Roccasalva said.
Independent Police Review Authority spokesman Mark Payne said a gun was recovered at the scene.
An autopsy is scheduled for later Thursday, the medical examiner's office said.
The IPRA and Calumet Area detectives are investigating.
"I had a policeman chasing a guy through my alley. He came and a policeman called him and I heard the rest of the gunshots," said Joshua Campbell, witness.
Customers rushed into BK's Barbecue to escape the gunfire.
"In the military, you hear a shot you hit the ground. You just start ducking. You don't care where it come from. You just start getting out of the way," said Eddie Robinson, witness.
The STNG Wire contributed to this report.