The newly obtained emails came in response to a court ordered Freedom of Information Act (FOIA) request that the DOJ had previously ignored. 

Via Judicial Watch (emphasis ours): 

Three days after then-FBI Director James Comey's press conference announcing that he would not recommend a prosecution of Mrs. Clinton, a July 8, 2016 email chain shows that, the Special Counsel to the FBI's executive assistant director in charge of the National Security Branch, whose name is redacted, wrote to Strzok and others that he was producing a "chart of the statutory violations considered during the investigation [of Clinton's server], and the reasons for the recommendation not to prosecute…"

[Redacted] writes: I am still working on an additional page for these TPs that consist of a chart of the statutory violations considered during the investigation, and the reasons for the recommendation not to prosecute, hopefully in non-lawyer friendly terms …