Sandra Bland, a 28-year-old Chicago woman, was found dead in a Texas jail cell last week. Cops say her death was a suicide; her family says it was murder. Now, authorities are releasing new details about her mysterious death, including a rough timeline of her final morning in jail.

Bland was arrested during a traffic stop July 10 for failing to signal a lane change. The encounter apparently escalated after she refused to put out a cigarette, and she was arrested and jailed, the New York Times reports. Bland was still alive, three days later, when a guard offered her breakfast around 6:30 am. By 9 am, she was dead.

The case is apparently being investigated as a potential murder and will likely be turned over to a grand jury, but in the meantime, a sketchy timeline—partially supported by video—has emerged.

The details, via the Times:

A Waller County sheriff’s official described a timeline for the jail cell of the woman, Sandra Bland, that started early in the morning of July 13, when she refused a breakfast tray around 6:30 a.m., until a jailer found her hanging shortly after 9 a.m. For about 90 minutes during that period, there was no movement by jail officials in the hallway leading to her cell, according to a video that the authorities released from a camera inside the jail. ... Capt. Brian Cantrell of the Waller County Sheriff’s Office said that Ms. Bland replied “I’m fine” when a jailer was conducting rounds shortly after 7 a.m. and later inquired about how to make a phone call. But shortly after 9 a.m., a female jailer saw Ms. Bland hanging in her cell and summoned help. Other officers and emergency medical personnel tried unsuccessfully to administer CPR.

Authorities also released a brief video clip of officers discovering Bland’s body Monday. Still, the evidence is far from conclusive: the surveillance cameras apparently covered only the hallway outside, so there’s no footage of Bland’s cell or cell door.

Cops say Bland committed suicide by hanging herself with a plastic bag, a conclusion her family says makes no sense.

Her relatives “make valid points” that Bland seemed to “have a lot of things going on in her life for good,” Waller County district attorney Elton Mathis tells the Times.

According to the AP, Mathis has asked the Texas Rangers, who are investigating Bland’s death, to perform “extensive scientific testing for fingerprints, touch DNA and use any other valid investigative techniques.”

The FBI is reportedly investigating the jailhouse hard drives to ensure the surveillance video wasn’t manipulated.