Is it possible that the University leadership/counsel would request LE serve the warrant to the OotR and that office would disseminate the information instead of having warrants fly willy-nilly around campus? (I don't know the answer to this, so I'm spitballing).
Edited to clarify based on convo w/NC Watcher below. It's only my job to confuse
@al66pine today. Everyone else is off the hook for today
No, it would be handled by the university leadership, mostly by the Office of General Counsel with the General Counsel and the Deputy General Counsel and others in that office. The registrar would normally report to the Provost and the Provost would work closely with the VP for Student Affairs, General Counsel, and President to coordinate the effort and gather informaton. The Chief Information Officer/VP for IT would also likely be involved. The Registrar is too far down the totem pole to play a role here, although s/he might be called upon to provide information regarding classes the students took (if any classes with WSU, for example), where the classrooms were located, who were the other students in the class (class rosters), etc. Or if there was ever a joint session in a class involving both U of I and WSU.
The registrar's office would collect data for IT reporting and reports regarding student retention based on various student demographics, as well as time-to-degree for various student demographics, also enrollment trends, classroom/facility needs, working closely with the Office of Institutional Research (IR). IT could also mean Instructional Technology, working with faculty on instructional technology needs. For example, if a faculty member needs a classroom with specific IT resources, the registrar's office would need to assign that class to a specific classroom/learning environment. IT often means Instructional Technology.
With regard to the "standards of conduct" statement on the Registrar's website, I imagine this would appear on pretty much every website at the university that students read, so that they are reminded of this over and over again. Especially the registrar's webpage, where students visit often. Standard protocol.
As NCwatcher stated above, the Division of Student Affairs is responsible for Student Code of Conduct/Standards issues, either the Dean of Students or the Vice President for Student Affairs.