Years ago, the ten-week GS-1811 Criminal Investigator Training Program (CITP) at FLETC (and the old INS Immigration Agent series course) didn't emphasize traffic stops, even though we had a few days of it (how to approach a vehicle, remove an uncompliant suspect, but that was minimal). Deliberate raid training and house clearing was stressed, not ad hoc hasty traffic checkpoints.
In this madness, clever federal agents would employ the experts at traffic stops and DWI checkpoints-- the local police.
Local and state police are more trained and experienced and have the right tools: orange traffic cones, spotlights, and heavy patrol cars.
Once the local police have channelized vehicles into a single lane at a checkpoint, the federal agent would then ask the driver for proof of citizenship or residency. If cleared, the agent tells the the police officer who takes over with instructions for the driver.
"Please go straight on, Ma'am." And he visibly signals "OK" for all to see.
If not cleared, the agent tells the officer to pull them over.
"Please pull to the side here, Sir." And he visibly signals "86-er" for all to see.
These ad hoc teams of ICE agents who never worked together before or conducted rehearsals are why these stupid senseless tragedies happen. Plus the lack of quality personnel.
LOL now we have a dumbs*&^ chiming in with taxes = theft.