Footage has emerged of police allegedly slamming the head of Sandra Bland to the ground as she was arrested just days before she committed suicide in jail. Sandra Bland, a Chicago civil rights activist, was found dead in her cell at Waller County Jail in Texas. She had been booked three days earlier on grounds of assaulting a public servant after the fraught arrest by the side of a highway, during which she angrily accused officers of harming her. An autopsy performed a day later classified her death as suicide by hanging – though friends and family have said there is no way Bland would have killed herself. Bland was part of the #BlackLiveMatter movement and posted videos about civil rights and racism on social media.Now a video has emerged showing the moment the Ms Bland was arrested after being pulled over by police during a routine traffic stop. Ms Bland was driving near Texas Prairie View A & M, after moving from Illinois to start a new job at the university in Texas. The clip, filmed by a bystander, shows at least one officer holding Ms Bland to the ground. She can then be heard angrily saying to one of the officers: ‘You just slammed my head into the ground. Do you not even care about that? I can’t even hear.’ As she is led to the waiting police car, she adds: ‘You slammed me into the ground and everything.’ Now Texas Rangers have confirmed that they are to conduct a thorough investigation into Ms Bland’s death after family and friend question the results of the autopsy. LaVaughn Mosley told ABC NEWS ‘We’re very suspicious and we’re a tight community and we’re very upset that this has happened and it seems like there’s nothing being done about it.’ While one of her longtime friends LaNitra Dean added Ms Bland was a warm, affectionate and outspoken woman, who often ‘spoke out about police brutality’. She added: ‘The Waller County Jail is trying to rule her death a suicide and Sandy would not have taken her own life. Sandy was strong mentally and spiritually. Meanwhile the hashtags ‘#JusticeForSandy’ and ‘#WhatHappenedToSandyBland’ have also been posted on Facebook and Twitter that question the ruling. Waller County District Attorney Elton Mathis added: ‘I understand there’s some disbelief among some friends and family that she would do this to herself. ‘That’s why it’s very important a thorough investigation is done and that we get a good picture of what Ms. Bland was going through the last four or five days of her life.