Sandra Bland, a 28-year-old black woman from the Chicago area, was pulled over on July 10 in Prairie View, Texas, northwest of Houston, for failing to signal a lane change.
The 52-minute video, released by the Texas Department of Public Safety, shows the trooper, Brian Encinia, approaching the car and asking if Bland is irritated. Bland replies that she is upset about being stopped for such a minor issue.
After running a check of Bland's driving history, the trooper returns and asks her to put out her cigarette, which she refuses to do, saying she has the right to smoke in her own vehicle.
At that point, the video shows Encinia demanding she leave the vehicle and then trying to pull her out. He then points a Taser and shouts: "I will light you up".
Bland asks at least 10 times about why she is being arrested and for what offense before Encinia replies she is resisting arrest.
She is heard telling the trooper: "I can't wait until we go to court."
Bland, who was taken into custody and later charged with assaulting an officer, was found hanging in her jail cell with a plastic trash bag around her neck three days later.
He then points a Taser and shouts: "I will light you up"
Her death was originally ruled a suicide. But her family, while acknowledging that Bland previously posted a video blog saying she was struggling with depression, has dismissed the idea she was suicidal. Family members said she was excited about starting a new job at her alma mater, Prairie View A&M University.
Waller County District Attorney Elton Mathis said on Monday he would investigate her death as a homicide. The state trooper, Encinia, has been has been put on desk duty for violating protocol in the arrest, officials have said.
"I am angry because of the way she died. All I want to know is why"
Demonstrators have protested outside the jail where Bland died and her case has been taken up by activists who say it is the latest example of racial bias and excessive force by US law enforcement. The trooper involved in the incident is white.
Bland's family has called for an independent autopsy and involvement by the U.S. Department of Justice in the probe of her death. A memorial for Bland was held at Prairie View A&M on Tuesday night attended by about 300 people.
"I am angry because of the way she died," Bland's mother, Geneva Reed-Veal, said at the memorial. "All I want to know is why."
Lawmaker questions arrest
A Texas lawmaker, speaking at a news conference on Tuesday, said the video suggested Bland should never have been arrested in the first place.
Democratic state Senator Royce West said there would be no cover-up in the investigation, which other officials at the news conference said could take time.
Jailhouse video released earlier by the Waller County Sheriff's Department shows a space of about 90 minutes between the last physical check of Bland in her cell and her being discovered dead at about 9 a.m. on July 13.
The jail was decertified last Thursday because of problems with staff training and observing inmates, including following state requirements for face-to-face checkups on inmates every hour, said Brandon Wood, executive director of the Texas Commission on Jail Standards.
Waller County Sheriff Glen Smith, who could not be reached on Tuesday for comment, previously told Houston's KHOU TV that he did not think either problem played a role in Bland's death.