A post-mortem on a woman who died in a Texas prison cell has found that her injuries were consistent with suicide.
Marks on Sandra Bland’s neck suggested she killed herself, said Waller County prosecutor Warren Diepraam.
About 30 cuts on her left wrist were likely to have been self-inflicted some weeks before, he said.
Bland was found dead by prison staff on 13 July, three days after her arrest, but her family say she would not have killed herself.
A video of the arrest shows a police officer pulling over the 28-year-old for not signalling when changing lanes.
After issuing a ticket, a confrontation follows when Bland refuses to stub out her cigarette or get out of the car.
As the action moved off camera, she can be heard saying the police officer slammed her head to the ground.
But Mr Diepraam said there were only some lacerations and abrasions consistent with being handcuffed.
There were no “defensive injuries” usually found in a murder, he added.
Jail records show that Bland told a member of staff she had attempted suicide in the past.
But guards assessed her and determined she was not suicidal when she was booked into the county jail.
State officials and the FBI are investigating her death.
It also emerged that Bland phoned a friend from jail to say she was “at a loss” over her arrest.
In a voicemail obtained by the US TV network ABC, Bland said she could not understand why a traffic violation had led to her detention.
In the message to a friend she said: “I’m still just at a loss for words, honestly, about this whole process. How did switching lanes with no signal turn into all of this?”