After reading carefully the three different hypos on our homepage, I have decided I would likely publish all three stories to some extent.
For instance, in the first hypo, as long as names are not mentioned specifically, I don't see how listening to that attorney would do any good. What purpose would it serve? The community needs to know something like a poisoned reservoir. They can be on the lookout or they may have more information to provide.
As for the second hypo, I would report that the police are questioning a new suspect. I would not use a name, unless the police publicly released it. I see no reason to hide this information from the public, especially if no identifying information is used. Note: I would not publish anything learned through his file. That is sneaky and unethical.
Lastly, the third hypo is a bit more tricky because no police have been involved. However, I think since this involves a school and sexual misconduct something needs to be published about it. If the man has a record or history of abuse he has no business in a school and parents have a right to know in order to protect their kids. Nevertheless, I would be careful about the exact information I publish, sticking to facts and official, named sources.
At the end of the day, I think as long as we can look ourselves in the mirror as journalists. And it is also important not to knowingly break laws just to get a story. But overall, the code of ethics we each hold should let us sleep at when dealing with these kinds of close calls.