[mindslight]

Taking a guess, the reason they're kidnapping many people just to release them without charges is because they're fishing for people with out of state IDs to strengthen the claim of federal jurisdiction. The lack of arrest paperwork fits with this - if they kept a paper trail of all their plainly unlawful attempts, it would risk upsetting whatever narrative they use to charge the unlucky ones.

[throwaway_USD]

It may also be partly about proactively anticipating civil lawsuits for false imprisonment and other violations of civil rights. If there is no record of these arrests it will frustrate future civil claims, where the Feds will just deny ever arresting claimants and for the most part unless on video there will be no evidence of the claim.