HEMPSTEAD, Texas — A grand jury decided that neither sheriff’s officials nor jailers committed a crime in the treatment of a black woman who died in a Texas county jail last summer, but has not yet determined whether the state trooper who arrested her should face charges, a prosecutor said.

Prosecutor Darrell Jordan said Monday that the Waller County grand jury will return in January to consider whether to indict the trooper who arrested 28-year-old Sandra Bland in July.

The Chicago-area woman was pulled over July 10 for making an improper lane change. Dashcam video showed the traffic stop quickly became confrontational, with trooper Brian Encinia at one point holding a stun gun and yelling at Bland.

Her arrest and death came amid heightened national scrutiny of police and their dealings with black suspects, especially those killed by officers or who died in police custody.