They weren't wearing badges when they were standing outside. They put on their vests when they made the arrest.

Basically, the cops are going as low key as possible because they know that the prosecutors, judges, lawyers, and even bailiffs are engaging in criminal obstruction of justice to protect criminals who need to be deported.

Basically, they are doing the minimum required because they know how much of a fight it's going to be.

And yes, they can detain American citizens if they are engaging in obstruction. "De-arresting" people is not only not illegal, but felonious.