They have been very up front that he nor his family are suspects. They even pointed out he was overseas when the DL took place.
That's an attitude that was missing in the Fogle case, which the feds were criticized for, but now we know why they didn't make such a statement there...
“Activism is a way for useless people to feel important, even if the consequences of their activism are counterproductive for those they claim to be helping and damaging to the fabric of society as a whole.” - Dr Thomas Sowell