I'm not crossing them off, believe me. They're number one on my list. Still, I try to incorporate any and all information, even unsubstantiated. I fully admit what I speculate is completely useless and helps nobody. I just like speculating -- I'm an analytical person.
The FBI held the Unibomber note secret for a long time. Once they released it, his brother recognized him in it.
But cops, like all bureaucrats, protect their turf, so they'll not release the info until the press forces them into it, as here happened with the threat to our children.