There were divers at FWF and Fred confirmed they were looking in bodies of H2O, albeit, small areas of H2O.
What do criminals usually throw into lakes, rivers, and ponds? Guns usually. They sink, where other items may not. So one guess I have is they were looking for weapons/items that would sink.
Also they were at the Etna cemetery bordering FWF property. Due to the fact they had metal detectors they may have been looking for weapons buried in the cemetery, guns would really alert a metal detector.
It is telling that Rita did not sign the custody documents. Why not ask her to sign? Well maybe Angela asked her but she refused. Also, it could be Angela didn't ask her because Angela knew she wouldn't do it or wouldn't approve, or Angela just wanted to keep her mom in the dark.
Because Rita did not sign the documents I don't think Angela would be giving out any hints to her that they got rid of evidence at FWF. I don't believe Angela could trust her mom with deadly secrets. She did not even know if her mom would or would not testify against them. She told her mom not to, that she did not have to do it.
Don't know about Fred, I think she would keep any and all deadly secrets but don't know when and how much she knew. She was right there during revenge talks in her own home which means she currently knows some secrets. How could she not?
I think she changed her story about knowing the Rhodens because she needs to distance herself from that entire family because she knows something she is uncomfortable knowing, a secret she is trying to "run" from.
...Opinions...
... " the truth is never far behind I've kept it hidden well... "
..." the secrets that I hide, will they grow cold?
How will they see? When will they learn? How will they know? "
... " the truth is never far behind they must be doing well... "
Madonna, At Close Range a true story, chilling theme song