"Cases".. plural... that's interesting.
I'm not sure why revealing the source of information - information which may not even be relevant - regarding the disappearance of a man 10 years ago who has been legally declared dead would have a detrimental effect on pending cases. Unless the cases are somehow tied into the Gricar disappearance, or unless the source(s) or your information could be disciplined for leaking information (which could later be used against them as a means of damaging their credibility in a possibly unrelated case). If it is the latter, I have to wonder what they gain from leaking info to you? Are you positive they aren't feeding you misinformation meant to protect them? I mean, if they came to you with info, they presumably knew you would post it, and that presumably means they wanted the info out there. So why not go to Sara Ganim, who has a much larger readership?