The easiest investigation ever...

They do their own payroll and report to the IRS with specific employer codes like every other agency. The ones out doing stops or working in camps will have a bunch of overtime, likely hazard pay, and special retirement deductions due to not being behind a desk.

There was never any way for them to be anonymous like the media pretended.

Then you just press all of them at once. Send FBI agents to every fucking door, with only one question:

Do you have anything you want to tell us?

They'll be tripping over each other to snitch on the worst to save themselves, and the worst will snitch on everyone else out of spite if nothing less.

Especially considering how documented their actions were, we don't need to trust their stories, just identify themselves and the other people on video with them.

Shits not complicated, we just need people who want to try