Sex offender charged with gathering porn on UI computer

Here's the story:
GazetteOnline - Sex offender charged with gathering porn on UI computer

Here are my questions:
* What was the amount of time between the viewing of the material and when the police came asking for records?
* How often does the library clear out the cache and history files of their public computers?
* What is the library's policy on supplying such information to the police?
* Did the police have a search warrant, subpoena, or other legal document requiring the library to give up such information?
* I'm sorry, but one does not "find" child pornography in the library. You might use a library computer to access it but "find" implies that the library carried/offered it.

I'll actually be in Iowa City in two weeks. I'm considering stopping by to see if I can find any answers to these questions (time allowing). If you know anything about this story I'd love to hear from you.