Police detectives on Sunday night were interrogating a suspected gunman after five people were shot dead in the Northwest Side's Dunning neighborhood, CBS Chicago reports. The shooting happened around 5:30 p.m. Saturday in a condominium complex, police said.

Investigators say a 67-year-old retired construction worker, who lived in the building for about 15 years, exited his own apartment and walked into a neighbor's apartment. He shot four people who were seated at a table eating dinner there, killing them all, police said.

He then went upstairs to the third floor, entered another apartment and fatally shot a woman there, police say. That woman was first taken to the hospital in critical condition, according to police officials, but she also died late Saturday.

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The Cook County Medical Examiner's office has identified two of the five victims. One is identified as Tsvetanka Kostadinova, age unknown, and another is identified as Jolanta Topolska, 53.

The shooting happened around 5:30 p.m. Saturday in a condominium complex, Chicago police said. CBS Chicago

Kostadinova was killed by a gunshot wound to the chest, as were two other victims, the Medical Examiner's office said. Another victim died of multiple gunshot wounds, and another died of a gunshot wound to the abdomen, according to the Medical Examiner's office.

While the Medical Examiner's office had not released the names of the other three victims, crosses set up in front of the condo building identified two of them as Danail Mladenov and Ivaylo Popov.

Meanwhile Sunday, CBS Chicago's Jeremy Ross got a firsthand account Sunday from someone who said he is lucky his family made it out alive.

"I looked outside and I saw all the squads over here, and the paramedics," said Jack Hunter, who became emotional as he spoke. "People called me up and friends, to make sure we were OK. And like it's shocking, so you wake up, and wow, it's reality."

Another man, who did not want his face shown on camera, said his wife first told him somebody was shooting.

"I went to check what's happened, so I try and go out from side door, and my wife stopped me, but I was already by the door… I saw the guy. I saw he was coming. I saw his face. I saw his eyes. He was looking at me. I was looking at him. And I know he's coming," he said. "So I didn't have my door locked, so I just locked my door. I grabbed my wife, and we start running for another exit."

He described the chilling moments when he thought his family was about to be part of the casualty count.

"I was face to face by this man," he said, also getting emotional as he added that he thought he was lucky to be alive.

"We didn't know where the guy was. I didn't know where the guy was," added Hunter.

At the cross memorials set up where the crime scene tape once stretched, neighbors – some of whom did not know the victims – shared prayers and candles at the site.

"It's a shame," Hunter said. "You can't go anywhere nowadays without, you know, maybe losing your life."

Investigators recovered the shooter's handgun and are looking into how he got it. But gunman's motive remained under investigation Sunday night.

"I guess the guy has anger issues or something like that, I think," Hunter said.

The man who asked to remain anonymous said the alleged gunman had raised red flags for him before.

"Before, I was scared – saw him every day on the stairs when he was passing by. Police coming a couple of times. The police couldn't do anything with him," he said. "Now maybe I'm not scared, because he's gone."

Despite police being aware of past issues, those concerns were described as minor. The 67-year-old alleged gunman has no apparent criminal record in Cook County.

The prior behavior was not reported to police and involved incidents of noise disturbances, exchanging dirty looks and bumping into each other. Police say the attack appears to be targeted, but once again, the motive is unclear.

As of Sunday afternoon, police were conducting a formal interrogation with the suspected gunman and were conferring with prosecutors from the Cook County State's Attorney's office on charges, police said.

Police said there is no timeline one when charges could be filed.