Aaron Dean Trial Day One: Atatiana Jefferson's nephew testifies, lawyers give emotional opening statements

The murder trial of former Fort Worth police officer Aaron Dean got underway Monday morning in a Tarrant County courtroom.

Dean is charged with murder in the fatal shooting of Atatiana Jefferson in 2019.

The former Fort Worth officer was escorted through the hallway amid tight security. Spectators' cell phones were collected before entering the courtroom.

"You are going to hear that this was an absolute intentional act, an unjustifiable act that never should've happened," said prosecutor Ashley Deener during opening statements.

ATATIANA JEFFERSON COVERAGE

Deener laid out the state's case with emotion, giving an overview leading up to the single shot that killed Atatiana Jefferson.

A non-emergency call was about the home's open front and side doors, with the lights on. Dean and another officer responded, going into the backyard where Dean fired his gun through a window.

"He sees something, he turns, and you will hear, ‘put your hands up, show me your hands, boom'. And I’m talking about, ‘show me your hands, put your hands up, boom’. It is not fast enough for Atatiana to process and follow the commands," said Deener.

Dean's defense follows suit.

Attorney Miles Brissette encourages jurors to focus on the information Dean had upon arrival: an open structure call, not a welfare check. He then referenced the city's police officer training guide and that Jefferson was holding a gun.

"Signal 56 is an open structure. You go to that in the book, it says to treat it like a silent alarm. Burglary of a building," said Brissette. "As soon as Aaron enters the backyard he sees a silhouette in the window. Aaron sees that silhouette in the window and that silhouette has a firearm."

"He takes a half a step back, gives the commands per training, draws his weapon. The first and only time right then and fires one shot." Brissette continues.

Zion Carr, Atatiana's nephew was the first witness called to the stand. Carr was the only person in the home with her that night. He recalls cooking hamburgers, but they burned inside the oven.

[ATTORNEY: "What’d you do after all the smoke came from burning all the hamburgers?"]

CARR: "We opened up the screen door and let the smoke go out, we had paper and was going like that, so the alarm could stop."

Zion testified they forgot the doors were left open while playing video games. Then his aunt heard a noise in the backyard.

[ATTORNEY: "After she told you she heard a noise what did she do?"]

CARR: "She went to go get her weapon out of her purse."

[ATTORNEY: "Where was her purse?"]

CARR: "Next to her table where she worked at."

Under cross-examination he showed the jury how his aunt held the gun.

Zion struggled with some details and testified he doesn't remember hearing the gunshot, only seeing his aunt fall to the floor.

[ATTORNEY: "Did you hear anyone get shot that night?"]

CARR: "No sir."

[ATTORNEY: "Why don't you think you heard anything?"]

CARR: "I probably just don't remember it."

The jury was dismissed before noon. The trial is expected to begin with a new witness on the stand Tuesday at 9 a.m.

If convicted of murder Dean could face between 5 and 99 years in prison.

FOX 4 will have gavel-to-gavel coverage on Fox4News.com and our YouTube page, plus live updates from the courtroom throughout the day.

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READ MORE: Aaron Dean murder trial set to begin Monday after numerous delays

Atatiana Jefferson Shooting Timeline

The shooting happened on Oct. 12, 2019.

Atatiana Jefferson was babysitting her 8-year-old nephew at her mother's house.

A neighbor made a non-emergency call to police because a door was open with lights on.

Officer Dean arrived, walked into the backyard and saw Jefferson in a window with her gun in her hand. Dean yelled, "put your hands up! Let me see your hands!" before immediately firing a single shot, killing Jefferson.

The shooting led to protests against the Fort Worth Police Department.

If you have issues viewing the timeline click here.