The top boss over the Texas trooper who arrested Sandra Bland said there was reason to pull her over for failing to signal a lane change and told lawmakers Thursday that the trooper remains on the state payroll because the investigation is still playing out.

Bland was found dead in the Waller County jail on July 13, three days after her arrest. Authorities say she hanged herself with a garbage bag, a find her family has questioned. Her family and others also have criticized the traffic stop that led to Bland's arrest.

"There was a reason, if you look at it from a traffic violation standpoint," Texas Department of Public Safety Director Steve McCraw said, responding to sometimes pointed questions from lawmakers during a hearing at the state Capitol. "But again, I don't want to prejudge. I don't know what the trooper is going to say in terms of when he's interviewed. When the investigation is over with, I'll be able to assess."

He later told reporters that while he had not yet spoken to Trooper Brian Encinia, the Texas Rangers and FBI have interviewed the trooper.

The confrontation between Bland and Encinia swiftly escalated after she objected to being told to put out her cigarette. Bland, who was black, eventually was arrested for allegedly assaulting the white trooper.

Bland's death came after nearly a year of heightened national scrutiny of police and their dealings with black suspects, especially those who have been killed by officers or die in police custody.

McCraw told state lawmakers that Encinia remains on the state payroll because due process is necessary while an investigation continues into the July 10 traffic stop. Encinia has been placed on administrative duty.

Lawmakers said dashcam video of the confrontation should speak for itself. The video shows Encinia holding a stun gun as he says, "I will light you up!" after Bland refused to get out of her car.

"Texas taxpayers are paying him right now," Republican state Rep. Jonathan Stickland said. "For a lot of people it's pretty cut and dry what happened, and that's someone's liberties were stomped upon."

McCraw said his agency is working swiftly but would not commit to a timeline for when the investigation will be finished.

McCraw told lawmakers his agency holds employees accountable. Agency spokeswoman Katherine Cesinger said about 400 employees at the massive Department of Public Safety have been fired since McCraw took over in 2009, but she did not know how many of those were troopers.

Democrat Garnet Coleman, the black chairman of the House Committee on County Affairs, was the first Texas lawmaker to call a legislative hearing after Bland's death. Coleman said he called the hearing in search of answers about trooper protocols and jail standards.

"How does someone get pulled over for not signaling and end up dead in three days? It just doesn't compute," Coleman said.

The hearing began with the head of jail oversight in Texas telling lawmakers that the state is now looking at revising mental health screenings in county lockups.

Texas Commission on Jail Standards Director Brandon Wood said a major challenge for jailers is dealing with inmates with a history of mental health issues who don't appear to be in immediate crisis. Bland indicated on a booking questionnaire that she previously attempted suicide.

Officials say Waller County jailers didn't get additional mental health training they were supposed to receive.