The DoD doesn't have bank accounts..i know that sounds dumb, but it spends its money through the US Treasury…the Treasury is the "bank" for the DoD and all gov't agencies…the "forensics" would be looking at the treasury's systems…the DoD just keeps receipts and records of what they bought to back up or prove the expense and compliance with OMB rules.
Last year, the requirment to keep money related records was only 7 years…so, DoD records prior to 2010 don't even exist…they've been shredded. Starting last year, DoD is required to keep them for 10 yrs now. So even under new rules, that takes us back to 2007. The "forensics" has already been looked at via Treasury and the DFAS, which are like the "tellers" and account managers between the Treasury and the DoD.