I wondered if I should bother the cops with it. I'll do that.
You might also report it to the campus safety/police/etc if they handle that sort of thing. The student may assume it's lost at school and might try that.
Oh, and if you report it to Apple, or even your local Apple store they may actually be able to locate the owner for you. They certainly know who originally purchased it - whether they tell you (privacy issue) or whether the original purchaser sold it eventually might be a problem, but I'd bet that Apple has some sort of policy about reported lost property. They may only be able to send a message to the owner (via email) once you provide the serial number, and the owner would then come by and prove, via the lock screen, that they are the current owner. Apple might not do it at all, but it's another avenue to explore.
Added at: 10:02
Can't do it logistically. If they come ask us about it thats fine but we don't have the manpower to stop taking care of customers and deal with every random person who wants to try and scam an iPad. It's just not an option.
Probably, but if it were me I'd post it, then make them do some work. "Fill out this form, which describes the model, capacity, 3G or wifi, the lock code, and one piece of info that's on it that only you know (calendar, contact with phone#, etc) and your email, and we'll email you if it matches your description. It's in a safe location, so we cannot verify your ownership here."
Just hand them the paper, and at the end of the day, throw out all those that don't match the type and capacity (iPad 1 or 2 should be easy to figure out and 16G, 32G, or 64G should be printed on the back, 3G is easy to see if it's got the black strip on the top back, etc). Try out the lock password of the rest, and you're done.
When you visit with the police make sure to ask them what your reporting requirements are (do you have to post a notice of any kind, or is reporting to the police enough) and how long until it you can legally own it. Depending on how they run things, you may have to give it to them, and then return to claim it as the finder once the time period is finished.