CHICAGO (CBS) — It was him or us. That’s what a Chicago store owner is saying about shooting & killing a man he says was trying to rob his South Side business.

That man Demarcus Brandon, was also the prime suspect in the shooting of a Harvey police officer last month.

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Today, for the first time, we’re hearing from that store owner. He asked CBS 2’s Mai Martinez to conceal his identity and voice.

“The guy comes in wearing a ski mask. Instantly my heart dropped,” the owner said.

The owner and two colleagues were inside. The man behind the ski mask was Demarcus Brandon, a recent parolee who served time for armed robbery.

“I seen him reaching for a weapon, and he pulls out a gun, so I ran, and he’s like ‘don’t move.’ As I was running, in my head, I was like ‘please don’t shoot me. Don’t shoot.’ You know, I, I felt like I was going to get shot from the back.”

The owner ran to a back room to get his own gun and took cover behind a wall.

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From there he could see Brandon holding his colleagues at gunpoint in the front of the store.

The owner says when Brandon came around the corner with gun drawn, he had no choice but to open fire. He took position and fired 5-6 shots.

The gunman also opened fire. One of his shots hit the ceiling another hit a wall just feet away from the owner.

Four of the owner’s shots went through a display case. At least three hit Brandon, who fell back against this door before running out of the store and collapsing on the sidewalk.

The owner says he did what he had to do to protect himself, but he’s still haunted by it.

“I can’t sleep at night. I think about the moment over and over and over again.”

The owner says many in the neighborhood have been supportive following the shooting, but he’s also received threatening phone calls and signs saying “get out” have been taped to his store front.

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Despite that, he still wants to do business in the neighborhood.