But it was unclear what the officer, Aaron Y. Dean, saw when he looked into the window, which was obscured by the reflection of his flashlight on the glass, at least according to the body camera video released by the police. Mr. Dean has declined to give an interview to investigators, according to the arrest warrant, and his partner on the call said that she saw only Ms. Jefferson’s face in the window at the time of the shooting.

Mr. Dean, 34, resigned from the department on Monday and was arrested later that day. He was charged with murder. Prosecutors will present the evidence to a grand jury, which will decide whether or not to issue an indictment.

At a news conference on Tuesday, Ms. Jefferson’s brother, Adarius Carr, said the problems in the Fort Worth Police Department extended beyond the actions of a single officer .

“This rookie cop is not going to be the scapegoat for what happened,” he said. “Yes, he is going to take his punishment, but the system failed him. Whoever senior who was with him failed him. Whoever sent him out failed him. The training failed him. There is a lot that has to get fixed.”