DALLAS (CBSDFW.COM) – A man suspected in a deadly shooting at an apartment complex at 2323 N. Field Tuesday morning, was later shot and killed in South Central Dallas.

Sources say it’s not clear if officers shot and killed him or if the suspect killed himself.

The first incident happened just after 10:15 a.m. at the North End Apartments, in the 2300 block of North Field Street, just north of the Perot Museum of Nature and Science.

Dallas Police said the suspect, identified as Marlon Smith, 29, was a former security guard who had been fired.

Smith was at the apartment complex on Monday trying to get his job back, but the office manager refused.

The former security guard allegedly returned Tuesday, shot the apartment manager and then took off.

The manager, identified as Nancy Churchwell, 52, was found dead at the scene by off-duty officers who live at the apartment complex.

Around 1:00 p.m. police found Smith, he got out of his car and pulled out a handgun.

He got in a gunfight with two Dallas Police officers and a U.S. Marshal in the 2100 block of Hulse Street.

Dallas Police Chief U. Renee Hall said a bullet struck a Dallas Police cruiser but no officers were hurt.

It’s not clear who shot and killed the Smith, but he was dead at the scene from a gun shot wound.

Chief Hall said Smith has a history of unlawfully carrying a weapon and marijuana possession.

“It doesn’t sit well and it disturbs us as a community as a whole when we hire individuals to protect us and then they turn around and become the individual that puts us in harms way or actually harms us,” Chief Hall said during a news conference Tuesday evening.

Friends of Churchwell and fellow employees sobbed outside the apartment complex, remembering the victim’s professionalism and kindness.

They say she usually had treats out for everyone in the lobby.

“Sometimes you would get cookies,” said resident Curtis King. “She said that’s always the way to invite people. She was an absolutely amazing human being.”

“She was a wonderful person to work with. That’s why we renewed our lease,” said resident Hunter Polvi. “Of all the managers I’ve had, I’ve never worked with anyone who was better at her job than her.”

“When something like this happens, it’s a huge shock. It’s like an earthquake,” said Kendrick McMahan, who knew both Smith and Churchwell.

McMahan and Rita Evan both live at the complex where the shooting started.

“I still can’t wrap my head around it,” said Evans.

Both said they saw Smith and Churchwell nearly every day.

“She was just always friendly, always nice, always involved with her community and this was her community,” said Evans.

Flowers and cards were left outside Churchwell’s home as family and friend remembered the energetic and thoughtful person.

“Nancy was a very special person and we’re going to miss her an awful lot,” said McMahan.

McMahan and Evans were unaware of any issues but knew Smith was no longer working security at the complex.

McMahan and Evans both said they never saw a negative side of Smith.“He was like a son to me actually. He was always nice,” said Evans.

McMahan added, “He always had a smile on his face, was never grumpy or seemed angry at all.”

Investigators are still trying to fully understand a motive for the shooting.

CBS11’s Yona Gavino contributed to this report.