Story highlights DOJ expands investigation in 2013 death of Kendrick Johnson

Assistant U.S. attorney: Investigation is "yet to ripen into an indictment"

Johnson, 17, was found dead inside a gym mat

Atlanta (CNN) It has been more than two years since the Department of Justice launched a criminal investigation to determine how Kendrick Johnson's body ended up in a rolled gym mat at his Georgia high school in January 2013. Now, newly released court documents reveal the widening scope of the ongoing federal probe.

United States Attorney for the Middle District of Georgia Michael Moore launched the investigation in October 2013 to determine whether the teen's death involved any "interference with federally protected activities" and if there was an element of conspiracy, according to the documents provided to CNN by the Lowndes County Superior Court. However, DOJ's investigation has "expanded" to investigate claims of witness harassment and obstruction of justice.

Targets of the federal investigation

The teen's parents never believed the local authorities' explanation that Johnson, 17, got stuck in the mat after diving in to retrieve a shoe. The state medical examiner concluded Johnson died as the result of accidental positional asphyxia. His parents, Kenneth and Jacquelyn Johnson, later had his body exhumed. They hired a pathologist who found evidence of "unexplained, apparent nonaccidental blunt force trauma" to the neck and concluded his death was the result of a homicide.

In January, Johnson's parents filed a $100 million civil lawsuit against dozens of local and state officials and named, among others, former schoolmates Brian Bell, Branden Bell and the Bells' father, FBI Special Agent Rick Bell, as defendants of a wrongful death claim.

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