ATLANTA — The family of a Florida man who died after Georgia sheriff’s deputies repeatedly used their stun guns on him in the back of an SUV alongside an interstate is asking for a federal investigation into his death.

Attorney Chris Stewart, who represents the family of Chase Sherman, said he sent the request Tuesday to the Civil Rights Division at the Department of Justice.

Sherman’s mother called 911 on Nov. 20 as they traveled on Interstate 85 from the Atlanta airport to their home in Destin, Florida. She said her 32-year-old son was “freaking out” and had taken a synthetic drug known as spice.

Video from Coweta County sheriff’s deputies’ body cameras shows the deputies struggling with Sherman in the back of an SUV until he’s still and they later realize he’s not breathing. Sherman was later pronounced dead at a hospital.

Stewart says Coweta Judicial Circuit District Attorney Peter Skandalakis has taken too long to decide whether to present the case to a grand jury.

Skandalakis said Wednesday that he hopes to reach a decision soon on whether to prosecute the case. He added that he would welcome the Department of Justice’s involvement in the case and would gladly share his files with federal investigators.