The report by the DOJ's OIG can be found here:

We also found that the cryptocurrency spreadsheets lack necessary inventory management controls to prevent and detect fraudulent or erroneous alteration of the inventory records, such as the ability to track edit history. Finally, we found that the inventory spreadsheets the USMS uses to track and manage seized cryptocurrency were not accurate. Based on our analysis, we identified 28 seized cryptocurrency assets in the USMS’s inventory spreadsheets that did not appear in CATS and determined that the differences were due to tracking errors in the USMS’s spreadsheets. In our judgment, these errors occurred because the USMS does not conduct periodic inventory reconciliations between its supplemental spreadsheets and CATS to ensure that the inventories are complete and accurate. Without periodic reconciliations, seized assets could be mismanaged and inventory records could be fraudulently altered without detection.

Audit of the United States Marshals Service's Management of Seized Cryptocurrency
https://oig.justice.gov/reports/audit-united-states-marshals-services-management-seized-cryptocurrency
https://oig.justice.gov/sites/default/files/reports/22-082.pdf (PDF)