(CNN)Weeks after a grand jury chose not to indict the officer who shot Michael Brown, officials have released a new mound of documents from the weeks of proceedings. 

They include more witness interviews, an autopsy conducted by a Justice Department medical examiner, as well as radio communications from the day of the shooting, which CNN has reported on previously. 

The documents do not seem to shed any new light on the events that led to Officer Darren Wilson shooting Brown. 

On November 24, the day the grand jury's decision was announced, the St. Louis County prosecutor's office released thousands of documents from the proceedings. Among the details that emerged: Wilson fired his gun 12 times; the officer said he feared Brown could beat him to death; and Wilson said he was not carrying a stun gun because "it is not the most comfortable thing. They are very large." 

The latest document release does not include one notable element: the FBI interview with witness Dorian Johnson, Brown's friend who was with him at the time of his shooting. 

Despite the promises of St. Louis County Prosecutor Bob McCulloch, who had promised to make all witness testimony in the case public, McCulloch's office told CNN affiliate KSDK that it has kept some records secret at the request of federal authorities, who are still investigating the incident. 

Executive assistant Ed Magee said the office had "turned over and relinquished control" of the FBI's interview, according to USA Today. He said the FBI asked the county not to release records that are part of an ongoing federal civil rights probe. 
Was he shooting back?
 he feared Brown could beat him to death