(CNN) -- The U.S. Justice Department will not conduct a civil rights investigation in the case of a teenager found dead in a rolled-up mat at his southern Georgia high school, a spokesperson for that agency said Wednesday.

Kendrick Johnson, 17, was discovered dead last January 11 headfirst in a rolled wrestling mat in the Lowndes County High School gymnasium in Valdosta, Georgia.

The Justice Department's criminal division is aware of concerns about Kendrick's death, but after reviewing the investigative file, it determined there is not "sufficient indication of a civil rights violation to authorize a civil rights investigation," according to the agency's spokesperson.

"We have discussed this matter with U.S. Attorney Moore, and his office is continuing to monitor and evaluate this matter, including the second autopsy report," the spokesperson added, referring to U.S. Attorney Michael Moore whose jurisdiction includes Valdosta.

That second autopsy report, which was obtained by CNN on Tuesday, found that Kendrick died as the result of "unexplained, apparent non-accidental, blunt force trauma."

This report directly contradicts an autopsy conducted by the Georgia Bureau of Investigation that determined that Johnson's death was the result of positional asphyxia. The Lowndes County Sheriff's Office ruled that his death was accidental.

Questioning that cause of death, Kendrick's family sent copies of the second autopsy report to the Georgia Bureau of Investigation, the U.S . Attorney for Georgia's Middle District and Lowndes County Coroner -- as well as the U.S. Justice Department's criminal division -- for review.

"I want to do the right thing by the people and the county and all concerned; I'm just not sure we have enough information," Lowndes County Coroner Bill Watson said earlier this week. "I'm not about to refute anybody's findings because I'm not a doctor."

On May 1, a judge granted the Johnsons' request to exhume their son's body in order to conduct -- at their expense -- the independent autopsy.

That autopsy, done on June 15, found Kendrick had suffered blunt force trauma to the right neck and soft tissues "consistent with inflicted injury."

"This is unexplained -- most very, very likely inflicted, as opposed to something he caused himself, inflicted by another -- and therefore needs to be investigated as an open homicide investigation," said Dr. William R. Anderson with Forensic Dimensions in Heathrow, Florida, who conducted the autopsy. He characterized authorities failure to pursue the case as "mystifying."

The initial patient care report, written by EMTs with he South Georgia Medical Center Mobile Healthcare Service on the day Kendrick was found, pointed to "bruising (on) the right side jaw."

Yet a January 25 report from the Valdosta-Lowndes County Regional Crime Laboratory cited "no signs of blunt force trauma on Johnson's face or body." The autopsy results released May 2 by the Georgia Bureau of Investigation identified "no significant injuries."

Speaking earlier this week, Moore said his office has been working on Kendrick's case "for some time," though it had not launched a formal investigation.

"There are some members of the community that question the result," Moore said. "I want to make sure members of the community and the family and everyone involved has confidence in my work and my decision."