As federal agents increase their footprint in Minnesota, observers are hitting the road, following along. 

WCCO Photojournalist Tom Aviles watched as it happened Tuesday afternoon in Minneapolis. His camera was rolling as whistles echoed through the community, and cars followed block to block. Then, suddenly, they stopped as agents jumped out and took a man into custody.

Not far behind are observers documenting everything. Some outside their vehicle, others inside, ready to follow again once agents start driving. 

Angel Castillo Saldana considers himself an observer who says he's exercising a legal right to record and document.

"They are moving like cartel members, very corrupt," Castillo Saldana said. "I'm not following; I patrol my streets. I grew up in these neighborhoods."

Minneapolis Police Chief Brian O'Hara says that following federal agents is not unlawful unless you're committing some separate act that is illegal.

The message from O'Hara is clear: observing is a protected right, but laws are in place against certain tactics.

"No tailgating, speeding, running red light,s aggressive or reckless maneuvers," O'Hara said. 

As more federal agents arrive, observers are showing no signs of slowing down.

"I'm going to continue doing this work until we get justice," Castillo Saldana said.

City leaders continue urging calm and peaceful protesters as federal activity continues.