A security guard was shot and killed at the Walmart store in Margate, authorities said.
The shooting happened near the entrance of the store on 5600 West Atlantic Boulevard at about 7 p.m.
"I heard, 'Bang bang!' And the guy's on the floor!" witness Edward Jorgenson told Local 10's Ross Palombo.
"[I] Just heard gunshots, grabbed my kids and ran through the back," shopper Ayesia Floyd said.
Authorities said store cameras show Luis Jhon, a Walmart security guard, confronting a customer for stealing T-shirts.
That's when witnesses said the shoplifter shot Jhon.
"He was shaken, unconscious," said Jorgenson.
According to police, the suspect ran out of the store, straight past a Margate Police substation and a parking lot control tower.
Nearly two hours later, authorities said they found a man fitting the suspect's description dead from a self-inflicted gunshot wound inside a nearby Margate home. Authorities are now trying to confirm his identity.
Jhon was later pronounced dead at the hospital.