HEMPSTEAD, Texas — Police dashcam video shows a Texas state trooper tried to pull Sandra Bland out of her car, then drew his stun gun and threatened her after the woman who authorities say later killed herself in a jail cell refused to follow his orders.

The roadside encounter swiftly escalated into a shouting confrontation, the video released Tuesday shows, as the officer attempted to drag 28-year-old Sandra Bland from her vehicle, with the officer at one point saying, “I will light you up,” as he held the stun gun.

Days later, Bland was found dead in the jail cell in a case that has caused her family and supporters to dispute that she hanged herself with a plastic garbage bag, as authorities have said.

The video posted online by the Texas Department of Public Safety shows the trooper stopping Bland for failure to signal a lane change. After he hands her a written warning, the trooper remarks that Bland seems irritated. The Illinois woman replies that she is irritated because she had changed lanes to make way for the trooper’s car.

The conversation quickly turns hostile when the officer asked Bland to put out her cigarette and she asks why she can’t smoke in her own car. The trooper then orders Bland to get out of the vehicle. She refuses, and he tells her she is under arrest.