Now, many question whether she should have been arrested at all.
The dashcam video shows Texas state Trooper Brian Encinia pulling Bland over July 10 for allegedly failing to use her turn signal. What started as normal conversation gets testy after Encinia asks her to put out her cigarette.
"I am in my car. I don't have to put out my cigarette," Bland says.
"You can step on out now," Encinia replies.
Bland refuses to get out of her car, and the trooper opens her door and starts trying to pull her out of the vehicle.
What happens after that has ignited a debate about what the officer could have done versus what he should have done.
'For a failure to signal?'
In the video, Encinia tells Bland she is under arrest. She repeatedly asks why, but the trooper does not answer, other than to say, "I am giving you a lawful order."
They argue, then Encinia pulls what appears to be his Taser and points it at Bland.
He screams: "Get out of the car! I will light you up! Get out! Now!"
Bland then exits the car of her own accord, saying: "Wow, really, for a failure to signal? You're doing all of this for a failure to signal?"
Much of what happens next is not seen on camera, but the officer can be heard saying Bland is not compliant.
"When you pull away from me, you're resisting arrest," Encinia says.
A clearly upset Bland can be heard saying: "You're a real man now. You just slammed me, knocked my head in the ground. I got epilepsy you mother******."
"Good," he replies.
A female officer tells Bland she should have thought about that before she started resisting.
What's the legality here?
Technically, a driver can get arrested in Texas for simply failing to use a turn signal.
In the video, Encinia tells Bland he intended to give her a warning -- until she failed to comply with orders and repeatedly cursed at the trooper.
"You were getting a warning ... until now," Encinia says. "You're going to jail."
CNN law enforcement analyst Harry Houck said the trooper did have the right to ask Bland to get out of the car and then try to pull her out of the vehicle.
"The fact is an officer can make an arrest anytime ... you run a red light, parking ticket, anything like that," Houck said. "What he did was he notices she was agitated."
But Houck, a retired New York Police Department detective, said the video concerned him.
"The one problem I have was just that he told her to get out of the car because she wouldn't stop smoking."
CNN legal analyst Sunny Hostin said she advises people that "when you have a police encounter, you want to make it as short and sweet as possible."
"But I don't think that he had the right to ask her to get out of the car because not putting out your cigarette is not cause for an arrest."
Texas Department of Public Safety Director Steven McCraw said Encinia has been taken off the street and has been assigned administrative duties pending the outcome of an investigation.
"We have certain procedures in place, and he did not comply with those procedures," McCraw said. "One of the many procedures is letting the individual know in terms of what actions are going to be taken."
The director also said, "A DPS state trooper has an obligation to exhibit professionalism and be courteous throughout the entire contact, and that wasn't the case in this situation."
What's the response?
Emotions ran high as people across the country watched the video.
"Just watched about 20 minutes of Sandra Bland's traffic stop," one person tweeted. "(I don't know) if I've ever been so heated. I can feel my blood boiling."
"Half of my family (including my mother) works in law enforcement," Ashley C. Ford tweeted. "I am well aware of my rights. Sandra Bland should've never been arrested."
Encinia has not spoken out publicly about the incident. But he gave his account in his arrest warrant affidavit, as reported by CNN affiliate KPRC-TV in Houston.
The trooper wrote that Bland became "combative and uncooperative" and that she was placed in handcuffs "for officer safety."
"Bland began swinging her elbows at me and then kicked my right leg in the shin," Encinia said. "I had a pain in my right leg and suffered small cuts on my right hand. Force was used to subdue Bland to the ground to which Bland continued to fight back."
Encinia also wrote that Bland "was placed under arrest for Assault on a Public Servant."
Why problems with video?
The Texas Department of Public Safety released almost an hour of dashcam video. But in parts of the footage, the video is looped while the officer's audio continues uninterrupted.
For example, there are moments when a car or wrecker driver appears in the frame, suddenly disappears and then appears once again.
But the video of the traffic stop was not edited, according to Texas Department of Public Safety public information officer Tom Vinger. "There was a technical issue during posting later in the video, and we are working to correct," Vinger said Wednesday.
Murder or suicide?
While the video of Bland's arrest may be startling, it still doesn't explain how she died in jail three days later.
According to the Waller County Sheriff's Office, Bland was found "in her cell not breathing from what appears to be self-inflicted asphyxiation." She received CPR, and an ambulance came, but she was pronounced dead a short time later.
Authorities said Bland apparently hanged herself with a trash bag from a metal barrier that separated the bathroom from the rest of the cell.
There were no cameras inside her cell, but cameras in the hallway showed no one entering or leaving before the discovery of her body.
Bland's relatives said they don't believe the 28-year-old would have killed herself. They said she had just moved to Texas and looked forward to her new job as a student ambassador to the alumni association at Prairie View A&M University, her alma mater.
Waller County District Attorney Elton Mathis promised a through and exhaustive review of the case, which will be presented to a grand jury.
"It has not been determined at this point that this was a murder. This investigation is being conducted as a murder investigation would," Mathis said. "Whatever the ultimate determination may be, whether that's a suicide or a homicide, that will ultimately be decided by a grand jury."
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Mathis said Bland's family had made "valid points that she did have a lot of things going on in her life that were good."
But investigators were examining online videos posted by Bland in March in which she talked about battling depression and post-traumatic stress disorder, according to Mathis.
Sharon Cooper said her sister hadn't been diagnosed with either depression or PTSD and that her video message was intended to be inspirational to people feeling the same way.
The Texas Rangers and the FBI are also investigating Bland's death. VIDEO