VIDEO: Sister of Sandra Bland speaks out

CHICAGO (WLS) -- Sandra Bland's sister wants to know what led to the Chicago-area woman's death in a Texas jail. Sharon Cooper spoke exclusively with ABC7 Eyewitness News.

"I'm frustrated. I will be honest with you, we thought that in bringing Sandy home from Texas, that that would begin to give us a little closure, in terms of getting closer to her homegoing services, getting ready to put her to rest peacefully," Cooper said. She also wants people to remember Bland, whose funeral will be held Saturday, as a good person.

Bland was found hanging in a Waller County Jail cell three days after she was arrested during a routine traffic stop. The medical examiner ruled Bland's death a suicide. The Waller County district attorney is treating this case as murder investigation, which is standard in jail death investigations.

While newly-released jail records shed light on Bland's mental health, they also raise questions as to why the 28-year-old woman was left alone. In the paperwork, Bland wrote she tried to commit suicide last year and that she was on medication.

The Waller County district attorney released six pages of medical forms Bland filled out after her arrest. In them, Bland checked "no" when asked the question "Are you thinking about killing yourself today?" But on the next line, when asked, "Have you ever attempted suicide?" she checked, "yes" and wrote "2014", "lost baby" and "pills."

Cooper acknowledged Bland's miscarriage.

"She was down about it, yes. But I have to tell you, that was a year ago. And she made her peace with it and got past it," Cooper said. As for Bland's Facebook posts about depression and PSTD, she "was never clinically diagnosed with that," Cooper said.

Cooper also questions an autopsy results that Bland had a significant amount of marijuana in her system.

"What I'm trying to understand, is at the time of booking, would that not be discovered? That she had access to that?" Cooper said.

"We'd like for them to release their full autopsy. We just yesterday got text messages from the D.A. indicating that their first autopsy was botched and now they need to do another one," the family's attorney, Cannon Lambert Sr., said.

The district attorney in Texas plans to hold a news conference on the autopsy Thursday afternoon.

"I have to tell you that there are so many inconsistencies in what we've been provided as a team to date. Whether it's the jail documents that are noted as 8:17, even though it was expressly communicated to us that she was booked four hours prior to that time. Whether it's the documents that show she did not signs any of those documents at all," Cooper said.

"There's a whole lot of things that we just don't know. And it's not something that we're comfortable right now given the atmosphere just unilaterally accepting whatever they tell us," Lambert said.

The family is awaiting results of a second, independent autopsy.

Bland's family is also taking a closer look at dashcam video of her arrest. It shows the heated exchange between a state trooper and Bland after he stopped her for failing to signal a lane change.

Her family points to this encounter, not possible depression, as the reason Bland died.

That officer was assigned to administrative duties for the duration of the investigation.

Bland's funeral is scheduled for 9 a.m. Saturday at DuPage AME Church in suburban Lisle.

Police released the raw, uncut dashcam arrest video Wednesday:

Warning: Video contains explicit language.