There's a lot of friction between Nanos and FBI/Patel, but I don't buy your theory. The sheriffs elections here
have been very political. I live in Tucson and we definitely have had our problems with BP, ICE and Drumpf. When the FBI showed up here the first thing I thought was they're going to try and pin this on an Immigrant! They're going to plant evidence and frame some poor immigrant for this!** If they have a chance to do it, they're going to try to! I texted this to my friend and she said that's what she had just told her husband!
I really think it's more like Nanos doesn't trust the PATEL FBI, and doesn't want them taking control of the evidence and the investigation. I tend to agree! Having the skills, resources and manpower of the FBI is good /// but NOT with Patel in charge.
** See? Mexicans are murderers, rapists, drug dealers, etc!! And now they kidnapped the mother of beloved morning anchor Savannah Guthrie!