In the Federation Government, there's a regulation stating that to prevent corruption among Federation Government employees, all items requiring auction must be handed over to a third-party organization, like banks, for auction.
Meanwhile, the judicial authorities have the power to supervise the entire auction process, ensuring no other forms of corruption manifest.
In fact, it's not only the Ministry of Justice that can entrust banks to auction certain items; individuals can too.
Lynch certainly wouldn't handle these matters himself; he lacks experts in this area and doesn't have sufficiently professional companies. In other words, he's unable to accurately calculate the specific value of any collateral that Mr. Herbs brings forth, so he delegates this task to banking departments.
He doesn't need a bank to auction these items, just to appraise them and store the related documents and items in the bank vault.
