DALLAS (AP) — The case against a white Dallas police officer who shot and killed a black neighbor will be presented to a grand jury, which could decide on more serious charges than manslaughter, the district attorney said Monday as an affidavit provided a fuller description of the officer’s account.

Lawyers for the victim’s family questioned why it took three days for officer Amber Guyger to be charged and why she was so quick to use deadly force in her encounter with 26-year-old Botham Jean, who lived in the apartment directly above hers. She told authorities she mistook the neighbor’s unit for her own.

An arrest affidavit prepared by a Texas Ranger was released Monday, providing a narrative of what happened. It appeared to be based almost entirely on the officer’s account.

Guyger told investigators that she had just ended a 15-hour shift Thursday when she returned in uniform to the South Side Flats apartment complex. She parked on the fourth floor, instead of the third, where she lived, according to the affidavit, possibly suggesting that she was confused or disoriented.

When she put her key in the apartment door, which was unlocked and slightly ajar, it opened, the affidavit said. Inside, the lights were off, and she saw a figure in the darkness that cast a large silhouette across the room, according to the officer’s account.

The officer told police that she concluded her apartment was being burglarized and gave verbal commands to the figure, which ignored them. She then drew her weapon and fired twice, the affidavit said.

She called 911 and, when asked where she was, returned to the front door to see she was in the wrong unit, according to the affidavit.

Authorities have not released any 911 tapes related to the shooting.

The Dallas County medical examiner’s office said Jean died of a gunshot wound to the chest. His death was ruled a homicide.

Prior to the affidavit’s release, Jean’s mother said investigators had not given her family an account of what happened. Allison Jean told a news conference that she asked many questions but was told there are no answers yet.

The family hired attorney Benjamin Crump, who is best known for representing the families of Trayvon Martin and Michael Brown. Martin was the black 17-year-old who was fatally shot in 2012 by George Zimmerman, a Hispanic man who was his Orlando-area neighborhood’s watch captain. Brown, who was 18, was shot to death in 2014 by a white police officer in Ferguson, Missouri.

“Black people in America have been killed by police in some of the most unbelievable manners,” Crump said Monday at a news conference, citing “driving while black in our cars” and “walking while black in our neighborhoods.”

Now, he said, “we are being killed living while black when we are in our apartments.”

The family’s legal team also includes Lee Merritt, who has represented relatives of an unarmed black teenager who was shot in the back by a white police officer in June while fleeing a traffic stop near Pittsburgh.

The officer was arrested Sunday night and booked into jail in neighboring Kaufman County before being released on bond.

When asked why Guyger was allowed to surrender somewhere other than Dallas County’s jail, Dallas County District Attorney Faith Johnson said the decision was made by the Texas Rangers, who are also investigating. She emphasized, though, that her office will conduct an investigation into the shooting as well.