NEW YORK (CNS) -- On July 10, 2015, Texas State Trooper Brian Encinia stopped 28-year-old African-American motorist Sandra Bland in Prairie View, Texas, for a routine traffic violation. The Chicago resident was found dead in her Waller County jail cell the morning of July 13.

The documentary "Say Her Name: The Life and Death of Sandra Bland" explores her tragic and controversial death while also recalling Bland's enduring impact on those who cherish her memory. Engaging on a personal level, yet maddeningly inconclusive, "Say Her Name" premieres on the pay-cable service HBO Monday, Dec. 3, 10-11:45 p.m. EST.

Wife-and-husband directors and executive producers Kate Davis and David Heilbroner mesh interviews with family members and friends, attorneys and criminal justice officials with footage from a variety of sources -- including the police dashcam, cellphones and jailhouse security cameras -- to create a portrait of their subject and explain how she lost her life.

In addition, the filmmakers intersperse a series of personal cellphone videos Bland posted online in the years prior to her death. Showcasing her personality, character, spirit and advocacy for racial justice, these "Sandy Speaks" messages set "Say Her Name" apart from other, similar documentaries.

Bland had traveled to the town where she was arrested, northwest of Houston, for a job interview at her alma mater, Prairie View A&M University, a historically black land-grant college with Reconstruction-era roots. The first in her family to pursue higher education outside the Chicago area, the Villa Park, Illinois, native likely exuded a high level of confidence when she returned to the Texas community.

She was going to the grocery store when Encinia stopped her for failing to signal a lane change. After a bystander's cellphone footage of the officer aggressively subduing Bland went viral, an investigation of the incident contradicted Encinia's original account of what happened.

Encinia insisted that he arrested Bland for assault of a public servant because he believed he was in jeopardy. But his own dashcam footage revealed that the officer became needlessly aggressive when Bland complained before putting out the cigarette she was smoking.

What the documentarians view as an unfortunate miscarriage of justice escalated into a tragedy when Bland was subsequently found hanging from a trash bag.

The determination of the Harris County coroner's office -- the change in jurisdiction is never explained -- that Bland committed suicide is backed up by Waller County Sheriff R. Glenn Smith and District Attorney Elton Mathis. They argue she had a high level of marijuana in her system and was despondent both at losing her job and at her family's inability to post her $500 bond.

They also point out that she had previously been arrested for marijuana possession and driving while intoxicated, that this was not her first suicide attempt and that she had suffered a miscarriage 14 months prior to her death.

That reasoning doesn't square with the image the filmmakers consistently project of a vibrant, intelligent, strong and determined young woman. As Bland's attorney, Cannon Lambert, says: "She was such an advocate for people coming behind her. It (suicide) doesn't jibe." Sheriff Smith's alleged history of racial intimidation casts further doubt on the finding.

Beyond the references to violence, racism, drug use, suicide and miscarriage already mentioned, "Say Her Name" also includes some coarse language and a racial slur, though both these elements are presented in context. Still, the film is best for grown-ups.

The more adult viewers get to know about the documentary's articulate and likable subject, the less inclined they'll be to believe Bland took her own life. Ultimately, however, the filmmakers fail to produce enough evidence to justify this conclusion factually.

An independent autopsy didn't find signs of a homicide. The lack of fingerprints on the trash bag purportedly used in the hanging and a log fabricated by Bland's jailer appear to be the only physical evidence suggesting something was amiss with Waller County's investigation. But a stronger case for a coverup isn't forthcoming.

Thus, despite the sympathy it engenders for Sandra Bland and for the lamentable fate she suffered, in the end, "Say Her Name" disappoints.

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Byrd is a guest reviewer for Catholic News Service.