Kendrick Johnson's body was found in a rolled-up gym mat in January 2013. A federal grand jury is investigating the case.

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Kendrick Johnson was found dead inside a rolled-up gym mat in 2013

Federal marshals seized emails from a sheriff's office as part of an investigation

Cell phones and computers were also seized from a former classmate and his family

CNN  — 

Federal marshals seized emails from a Georgia sheriff’s office this week, more than two years after investigators there concluded there was no foul play when a 17-year-old was found dead inside a rolled-up gym mat.

U.S. Marshals came to Lowndes County IT offices Tuesday and Wednesday with a warrant and copied sheriff’s office emails related to the investigation into Kendrick Johnson’s death, an attorney representing the sheriff’s office told CNN.

The warrant was tied to the federal grand jury investigation into Johnson’s January 2013 death, Lowndes County Attorney Jim Elliott said. Elliott said he did not know which emails had been copied and declined to provide a copy of the warrant.

Lowndes County sheriff’s investigators concluded that Johnson got stuck while reaching for a shoe at the center of the mat in the Lowndes County High School gymnasium, and that his death was accidental. The state’s medical examiner agreed, citing “positional asphyxia” as the cause of death.

But a forensic pathologist hired by Johnson’s family determined the teen’s death was the result of a homicide, saying he found evidence of “unexplained, apparent nonaccidental blunt force trauma.”

The Department of Justice launched a federal investigation into Johnson’s death in October 2013, but authorities have been tight-lipped about what they’ve found.

Also seized: Family’s computers, cell phones

In January, Johnson’s parents filed a $100 million lawsuit that claims several former classmates beat their son to death.

The lawsuit – which also names members of local law enforcement and the city of Valdosta as defendants – accuses two former schoolmates, who are brothers, and their father, who is a local FBI agent, of wrongful death.

CNN is not naming the former students or their father because they have not been called suspects or been charged with a crime.

An attorney representing the brothers and their family told CNN affiliate WCTV that federal marshals also seized items from the family’s home and from one of the former students’ college dorm room this week, including computers, cell phones and other property.

Ron Hosko of the Law Enforcement Legal Defense Fund, which also represents the family, said computers, thumb drives and cell phones were seized.

“The case is built solely on suspicion, innuendo and rumor, not evidence,” attorney Brice Ladson, who represents the same family, told WCTV, noting that no one has been indicted in the federal grand jury investigation and that there’s no evidence that anyone from the family is involved.

Ladson did not respond to a request from CNN for comment.

Earlier this year he told CNN the FBI agent and his sons had received letters informing them they were targets of an ongoing investigation into Johnson’s death by the Department of Justice.

‘Following the facts’

Michael Moore, the U.S. Attorney for the Middle District of Georgia, also has not responded to a request for comment on the raids.

It’s unclear how many times the grand jury has convened since the investigation began or what the federal probe has unearthed.

Earlier this year, relatives and former schoolmates of Johnson testified before the grand jury. And witnesses were subpoenaed to testify in the case on at least two dates in 2014, according to documents reviewed by CNN.

“While our investigation has proven to be more complicated and taken longer than I had originally anticipated, we remain committed to following the facts where they may lead,” Moore told CNN earlier this year.

CNN’s Devon Sayers contributed to this report.