On Friday, police officers pulled over Sandra Bland, a 28-year-old black woman from Chicago visiting Texas for a job at her alma mater Prairie View A&M University in Waller County for failing to signal before changing lanes. Following some sort of altercation, police arrested Bland for allegedly becoming combative. She died in jail Monday morning of a reported suicide.

However, while the Waller County Sheriff's Office is calling it a suicide, Bland's friends and family are raising serious questions about what happened, given Bland was reportedly happy and showed no signs of depression or suicidal tendencies.

Adding additional questions to the case, video footage of parts of the arrest show two police officers exercising what appears to be disproportionate force and Bland pleading with them to stop being so rough. "You slammed my head into the ground, do you not even care about that?" Bland cried out to the officers. "I can't even hear."

The video also shows one of the officers trying to stop a passer-by from filming, despite their legal right to do so and intimidation to stop such recording is illegal.

YouTube

"After [the police officer] pulled her out of the car, forced her and tossed her to the ground, knee to the neck, and arrested her," Malcom Jackson, a friend of Bland's, told local television station WLS.

A press release from the sheriff's office on Facebook said, "a female inmate was found in her cell not breathing from what appears to be self-inflicted asphyxiation," and Texas Rangers are now investigating the death.

Mic attempted to contact the Waller Country Sheriff's Office which said they could not comment on the case as it is currently under investigation. The office did, however, send a copy of the press release posted on Facebook.

Longtime friend LaNitra Dean says those closest to Bland find it hard to believe she would kill herself. "The Waller County Jail is trying to rule her death a suicide and Sandy would not have taken her own life," Dean told WLS. "Sandy was strong. Strong mentally and spiritually."

Politically active: Bland was known in part for her social and political activism and was vocal about the Black Lives Matter movement, posting videos of herself discussing the matter on social media, in segments known as "Sandy Speaks."

Her most recent Facebook profile picture included the text "Now legalize being black in America" and a banner photo of a cartoon that references the difference in the way white and black people are treated during arrests, alluding to Charleston, South Carolina, shooter Dylann Roof's dignified treatment by police.

Bland also appeared to regularly use her Facebook page for posts that reflected her political activism and her concern black Americans are treated as second-class citizens.

Giving Sandy a voice: In the wake of Bland's death, a Baltimore resident started an online petition addressed to the Department of Justice and Attorney General Loretta Lynch, entitled "Take Over The Investigation Into The Death of Sandra Bland From The Waller County, Texas Police Department."

"Per all family, friends and peers who have spoken publicly on this matter — Ms. Bland was a very bright, vital and happy person with absolutely NO indications of depression or suicidal tendency whatsoever!" the petition reads.

A social media campaign calling for justice also began after Bland's death. #SandySpeaks and #WhatHappenedToSandraBland were trending Thursday with many Twitter users expressing outrage at her death.

As this case gains national attention, it may well induce an outside investigation of what happened.

Footage of portions of Bland's arrest can be seen here:

July 16, 2015, 11:10 a.m.: This article has been updated.