(CNN) When Atatiana Jefferson 's neighbor called police, he says he expected them to go check to see if she was OK.

But the officer who shot her in her own home was sent on a call that police often handle as a potential burglary.

Authorities are looking into what former Fort Worth police officer Aaron Dean and his partner were told before arriving to Jefferson's home.

"The information came from the neighbor to the call-takers and while it was relayed to the dispatch, it was determined to be an open structure call," Fort Worth interim Police Chief Ed Kraus told reporters on Tuesday.

Experts say that classification escalated things beyond a welfare check, and meant the officers would respond differently.

It could have been a burglary or other crime

Many times a welfare check involves a medical emergency, an elderly person living alone or a relative who is difficult to get ahold of.

For those calls, police officers usually knock on someone's door and wait for an answer. But the mindset of a police officer changes when they hear it's an "open structure" or "open door" call.

Michael "Britt" London, president of the Phoenix Law Enforcement Association, said officers have a more cautious approach and run through multiple scenarios in their heads. They could be presented with a simple case of a door left unlocked, an abandoned home, or a burglary in progress.

"You are at a higher sensitivity to what is going on with that house," London said. "You have to be ready for anything. You are taking more of your environment in consideration to be ready for a surprise if there's one."

The first thing that comes to mind is often a burglary -- that's why officers search for signs of forced entry like a broken window or a damaged door.

Body camera footage from that night shows Dean, 34, peering through two open doors and walking around the perimeter of the house. He then pointed his weapon at a window and yelled "Put your hands up! Show me your hands!" seconds before he opened fire, striking Jefferson.

He resigned from the department on Monday, and was arrested and charged with murder. His attorney, Jim Lane, told CNN the former officer is remorseful.

"My client is sorry and his family is in shock," Lane said.

'They never have both doors open'

Jefferson's neighbor told the Fort Worth Star-Telegram that he was worried to see a front door open late at night, so he called a non-emergency police line. But he didn't mention a potential burglary.

"Well, the front doors have been open since 10 o'clock. I haven't seen anybody moving around. It's not normal for them to have both of the doors open this time of night," Jefferson's neighbor said, according to audio of the phone call released by authorities.

"OK, do you know if anyone is inside?" the police call-taker asked him.

"I'm not sure. Both of the cars are there," he replied.

The neighbor went on to describe the vehicles and also confirmed his name and phone number.

"Are they usually home at this time?" the call-taker later asked him.

"They're usually home but they never have both doors open," the neighbor told her. "The lights are on, I can see through the house. My sister woke me up, she lives across the street from them. I live on the opposite side of my sister."

Officer's behavior was 'extremely concerning,' former chief says

Jeff Halstead, a retired Fort Worth chief of police and police consultant, said there was nothing in the body camera footage released after the shooting suggests there was a crime happening.

"They were standing literally at the front door, they could see whether the door was kicked on or not. The lights were on, there was evidence that people were living there, there were toys," Halstead said.

"Why they advanced to an extremely dark backyard area without at least ringing the doorbell or checking the entrance? That's extremely concerning."

Dean's experience as a police officer could have factored into how he acted during the call, Halstead said.

"Some officers, younger officers, think every call is an extreme risk or high profile call," he said. "With seniority, maturity, experience, you can customize your mindset in approaching a lot of different calls."

Dean was hired in August 2017 and commissioned as a licensed officer in April 2018.