When Sandra Bland, 28, was taken to the Waller County Jail in Texas, newly released intake forms show she disclosed having tried to kill herself the past year.
Bland checked "yes" to having attempted suicide by taking "pills," and cited "lost baby" as the reason.
The Texas Rangers have begun an criminal investigation to determine if Bland's death was a suicide or murder.
Family members and protesters claim Bland would never have attempted suicide, and say she never should have been arrested when she was pulled over on a routine traffic stop.
Bland and the Texas trooper got into an escalating argument that began when she failed to put out her cigarette.
Dash cam video shows the trooper ordering her out of her car and threatening to taser her. After she was locked in her cell, jail video indicates that no one checked on her during an hour-period of her death -- a violation of Texas jail standards.