Department of Justice prosecutors across the US have suffered a string of embarrassing defeats in their aggressive pursuit of criminal cases against people accused of “assaulting” and “impeding” federal officers.

In recent months, the federal government has relentlessly prosecuted protesters, government critics, immigrants and others arrested during immigration operations, often accusing them of physically attacking officers or interfering with their duties.

But many of those cases have recently been dismissed or ended in not guilty verdicts.

In several high-profile cases, the prosecutions fell apart because they relied on statements by Department of Homeland Security (DHS) officers that had no supporting evidence or in some instances were proven by video footage to be blatantly false.

Criminal defense lawyers said it was unusual for federal prosecutors to pursue a high volume of charges over minor clashes with law enforcement, and that it was extraordinary to see the DoJ lose case after case across jurisdictions.