Sandra Bland might have used marijuana in jail before she was found dead, it has emerged.
A toxicology report released on Monday shows the 28-year-old had 18 micrograms per liter of THC - one of the active components of marijuana - in her bloodstream when she was found hanged in her Texas jail cell on July 13.
Speaking to the Associated Press, Robert Johnson, chief toxicologist for the Tarrant County medical examiner's office, and University of Florida toxicology professor Bruce Goldberger both said that amount is high enough to suggest she used marijuana from behind bars.
"I don't think it's possible to rule out the possibility of use while in jail," Goldberger said, adding that she was impaired by marijuana at the time of her death.
Johnson said that a THC level that high suggests she either had access to marijuana behind bars or used it so often that her body had accumulated THC and was slowly releasing it.
But he added: "I have never seen a report in the literature or from any other source of residual THC that high three days after someone stops using the drug."
The amount of THC found in her system was more than three times the legal limit for drivers in Colorado and Washington, where the recreational use of marijuana is allowed.
Waller County District Attorney Elton Mathis declined to comment on the report but last week, one of his prosecutors, Warren Diepraam, said he wouldn't rule out the possibility of drugs being smuggled into the jail.
According to authorities, Bland took her life while in the Waller County Jail three days after she was arrested over a confrontation with a trooper during a traffic stop. Her family has said she would not have killed herself and called for an investigation.
The Texas Rangers and the FBI are both reviewing the case.
Watch Below: Sandra Bland Seemed Distraught, Inmate Says