I'm not saying they shouldn't be interested... What if, instead of simply being locked, the phone was eaten by a pelican that flew out over the ocean and died.

I'm not saying they shouldn't be interested... What if, instead of simply being locked, the phone was eaten by a pelican that flew out over the ocean and died. Gone. Should we dredge the ocean to find the phone? It's a duty to do so, right? The FBI have tried, and failed. How much more should they dredge before we stop harping on about this one piece of potential evidence? In this case they have the phone physically in hand so they feel blocked and powerless, but from a cost-benefit point of view it might as well be at the bottom of the ocean. Doesn't their duty compel them to investigate the most-likely to payout leads, not play political games over high-profile issues?