The family of Sandra Bland filed a wrongful death lawsuit on Tuesday against a Texas trooper, a sheriff’s office and her jailers, accusing them of being responsible for the woman's apparent suicide in a county jail.
The suit, filed in a federal court in Texas, said officials violated her constitutional rights. The family said it was seeking financial damages, but court papers did not specify an amount.
Bland, a 28-year-old African-American, was pulled over in her car on July 10 by a white state trooper, Brian Encinia, for failing to signal a lane change in Prairie View, about 50 miles northwest of Houston.
The discovery of Bland's body in her cell three days later with a trash bag around her neck in an apparent hanging provoked suspicions of racist treatment.
Local officials have said she was not mistreated in jail.
Still, her death has helped fuel growing criticism of U.S. policing amid a string of incidents involving the treatment of minorities by police across the United States.
The lawsuit said Encinia "intentionally, willfully, wantonly, and unreasonably deprived Sandra Bland of her rights, privileges and immunities secured by the U.S. Constitution."
In addition to Encinia, the suit named the Texas Department of Public Safety, Waller County, the county's sheriff's department and two jailers as defendants.
None of the defendants could be immediately reached for comment.
The Department of Public Safety has said Encinia acted improperly in the stop.
The stop escalated into a verbal altercation after Encinia asked Bland to put out a cigarette and she refused. Bland was arrested and charged with assaulting an officer, a felony, with the incident recorded by the police car's dashboard camera.
The suit also says her jailers did not do enough to protect her.
Bland's family previously acknowledged a Facebook post by the Chicago-area native in which she discussed struggling with depression, but they have disputed officials' suicide ruling.
"Waller County Jail personnel ... were willful, wanton, and reckless in exhibiting a conscious disregard for the safety of Sandra Bland in failing to keep her in a safe and suitable environment where she could be kept free from injury, harm, and death," it said.
A lawyer for the family told a news conference in Houston they are asking the U.S. Department of Justice to investigate. The Justice Department is monitoring the situation, the White House said last week.
"This family needs an answer to the principal question, what happened to Sandra Bland?" lawyer Cannon Lambert told reporters.
(By Jon Herskovitz; Additional reporting by Suzannah Gonzalez and Fiona Ortiz in Chicago; Editing by Bill Trott and Susan Heavey)