Who says you can’t. Get some Spanish speakers to work undercover and ask around. Do the research and then turn it in to an NGO such as Judicial Watch. No trusting the federales all by themselves.
I don’t expect any LE to do it. But it’s as simple as a citizen journalist watching who is handing out the box lunches as they get off the bus. Where do they sleep at night? Bet it’s at a Comfort Inn. Who is the night clerk, and who pays the bills? We, in the ground, take note of these transactions!