What does the newly released Sandra Bland video show?

New dashcam footage of Sandra Bland's arrest has critics questioning whether it has been doctored and why the trooper made physical threats.

"I will light you up!" 

That's what a newly released police video – which contains explicit language – shows a Texas state trooper saying as he points a stun gun at Sandra Bland, the woman whose death in her Waller County jail cell has left the public divided over whether she committed suicide, as officials have said.

Footage shows the officer, Brian Encinia, trying to drag Ms. Bland out of her car as what looked like a routine traffic stop unfolded into a dramatic confrontation. The officer told Bland that he had pulled her over for failing to signal before changing lanes. When he asked her to put out her cigarette, she replied, "I’m in my car, why do I have to put out my cigarette?” 

“Well, you can step on out now,” Officer Encinia said.

When he told her she was under arrest, she repeatedly asked why she was being detained for a traffic violation. Bland continued to refuse to get out of the car and the officer threatened to remove her by force and can be seen reaching into the car attempting to physically remove her from the vehicle.

“I’m going to yank you out of here,” Encinia said as the two struggled in the car. “I’m going to drag you out of here."  

She eventually complies after he threatens her with a taser.

When Bland does step out of the car, he orders her to the side of the road, where their conversation continues off-camera. But even out of the camera's view, viewers can hear Bland further protesting her arrest, swearing, and decrying the officer's tactics. She screams that he's about to break her wrists and says the officer “just slammed my head to the ground.”

Encinia said afterward that he had used force "to subdue Bland to the ground," and she continued to fight back, swinging her elbows at him and kicking him in his right shin, according to an affidavit released Tuesday. The arrest had been made on the charges of assaulting a public servant.

Some critics have cast doubt over the authenticity of the video, and even after seeing Bland's hostility, whether the officer's actions had been warranted in the first place. 

"A person's attitude or their demeanor is not probable cause to make an arrest," Vernon Herron, a senior policy analyst with the University of Maryland Center for Health and Homeland Security, said to the Associated Press, adding that the video had troubled him "from start to finish."

On his blog, writer Ben Norton said, "Parts of the approximately 52 minutes of footage it uploaded have clearly been doctored." He pointed to several parts in the video where footage appears to be looped. 

"Selma" director Ava DuVernay has also dismissed the video's legitimacy. "I edit footage for a living. But anyone can see that this official video has been cut," she tweeted.

What Ms. Duvernay said in response to critics perhaps best summarizes the views of those who continue to question Bland's death: "I disagree. Not worth arguing about. Because the real issue is: What happened to #SandraBland? Missing info from start to finish. Why?"

This report contains material from The Associated Press.

[Editor's note: The original version of this article incorrectly identified the location of Sandra Bland's jail cell. She was held in Waller County, Texas.]