Tarrant County Sheriff Releases Video and Timeline of Inmate Mack Greer's Death, Disputes Commissioner Alisa Simmons' Claims

FORT WORTH, Texas — Tarrant County Sheriff Bill Waybourn has released an official timeline and video evidence surrounding the June 2026 death of jail inmate Mack Greer, pushing back against allegations made by County Commissioner Alisa Simmons about the circumstances of his death.

Greer, 49, died June 18, 2026, after being transported from the Tarrant County Jail to John Peter Smith (JPS) Hospital, where he was pronounced dead.

The Tarrant County Medical Examiner's Office ruled his death natural, attributing it to moyamoya disease, a rare condition affecting blood vessels in the brain.

According to the sheriff's office, multiple agencies completed their investigations on October 13, 2026, approximately four months after Greer's death. The sheriff's office says an independent investigation found no wrongdoing by jail personnel.

The findings have intensified a public disagreement between Waybourn and Simmons, who called for an outside investigation following Greer's death and raised questions about his physical condition.

Mack Greer Was Booked Into Tarrant County Jail on May 28

According to the timeline released by Sheriff Waybourn, Greer was arrested by the White Settlement Police Department and booked into the Tarrant County Jail on May 28, 2026.

He faced a charge of theft of aluminum, bronze, copper or brass material valued at less than $20,000.

His bond was set at $1,000.

According to the sheriff's office, Greer was unable to pay the amount required to secure his release through a bondsman and was assigned to Unit 57B of the Tarrant County Corrections Center.

The sheriff's office stated that Greer was experiencing homelessness and had a criminal history dating to 1996.

Officials also reported that Greer had a lifelong condition known as moyamoya disease.

Greer remained incarcerated until his death on June 18.

Medical Examiner Rules Death Natural Due to Rare Brain Blood Vessel Disease

The Tarrant County Medical Examiner's Office determined that Greer died from moyamoya disease and classified the manner of death as natural.

Moyamoya disease is a rare cerebrovascular disorder involving the progressive narrowing or blockage of major arteries supplying blood to the brain.

The condition can interfere with normal blood circulation and increase the risk of strokes and bleeding in the brain.

The medical examiner's determination differs from allegations that Greer's death resulted from injuries inflicted by jail personnel.

According to the sheriff's office, independent investigators found no wrongdoing by detention staff.

Video by TCSO Detailed Timeline of Greer's Stay at the Jail

Greer Was Third Tarrant County Jail Inmate to Die in Four Days

Greer's death occurred during a particularly troubling week at the Tarrant County Jail.

He was the third inmate to die within a four-day period in June 2026.

The other two inmates were identified as:

• James Kent Johnson, 40

• Carl Avery McCray, 40

The deaths prompted concerns about jail conditions, medical care and oversight.

On June 19, one day after Greer's death, Commissioner Simmons publicly called for an outside investigation.

The causes and circumstances of Johnson's and McCray's deaths were not included in the sheriff's latest summary, and no connection between the three deaths has been established in the information provided.

Commissioner Alisa Simmons Questions Circumstances of Death

Simmons, a Democrat who has represented Precinct 2 on the Tarrant County Commissioners Court since 2022, has publicly questioned the circumstances surrounding Greer's death.

She is currently a candidate for Tarrant County judge.

In her public comments, Simmons described Greer as having suffered "fatal head injuries" and referred to his head as "misshapen," according to statements cited by the sheriff's office.

Waybourn disputes those descriptions and maintains that the medical examiner's findings do not support claims that detention officers caused Greer's death.

During a Commissioners Court meeting, the sheriff challenged Simmons over her statements about Greer's injuries.

Simmons disputed his characterization of her remarks and said she had not claimed Greer died from a head injury.

According to footage from the meeting, Simmons challenged him to produce video of her making the disputed statements, and he subsequently released footage in response.

The dispute centers on how Simmons' earlier remarks should be interpreted and whether they accurately reflected the available medical and investigative evidence.

Sheriff Accuses Commissioner of Spreading Misinformation

In announcing the release of the timeline and video, the Tarrant County Sheriff's Office sharply criticized Simmons.

The department accused the commissioner of politicizing Greer's death and spreading misinformation despite what it described as clear video evidence.

Waybourn said the accusations against detention staff were contradicted by the completed investigations.

"These accusations are not only false, they are a direct attack on the integrity and the incredible work performed daily by our detention staff under very difficult circumstances," Waybourn said.

"Spreading these misleading headlines and half-truths is highly irresponsible."

The sheriff maintains that the medical examiner's natural-death determination and the independent investigative findings support the position that jail personnel did not cause Greer's death.

Simmons' original call for outside scrutiny came before the investigations were completed. The information provided does not include a new response from Simmons addressing the October findings or the sheriff's latest video release.

Sheriff's Office Addresses Contact With Greer's Family

The sheriff's timeline also included information about attempts to communicate with Greer's family.

According to TCSO, Greer received no visitors during his incarceration.

The sheriff's office said a meeting had been scheduled between Waybourn and members of the Greer family, but the family did not attend.

Officials said the department subsequently contacted family members to reschedule and had not received a response.

Investigations Completed October 13

According to the sheriff's office, the investigations into Greer's death were completed on October 13, 2026.

The process took approximately four months following his June 18 death.

Waybourn says the release of the timeline and video is intended to provide transparency and correct public claims about the case.

The medical examiner's official finding remains that Greer died of natural causes related to moyamoya disease.

What is Moyamoya Disease?

According to the National Institute of Neurological Disorders and Stroke (NIH), Moyamoya disease is a rare, progressive cerebrovascular condition where the main arteries in the brain—specifically the internal carotid arteries—slowly narrow and block, restricting oxygen flow. To compensate, the brain grows a network of tiny, fragile collateral blood vessels that look like a "puff of smoke" on an angiogram. The key symptom in adults is that the patient is prone to ischemic strokes, seizures, chronic headaches, vision changes, or hemorrhagic strokes (brain bleeding) from ruptured tiny vessels.