Our campus MIS policy does not stipulate any "statute of limitations" for MIS
allegations.  Complainants may bring forward concerns about situations that
happened years ago, and have.  Circumstances might  dictate some elapsed time:
 --grad student in first year sees something, fears for graduation,
waits until receives degree to come forward--3 years later;
 --colleague notes a matter, discusses it with respondent and thinks it
is taken care of, 8 years later sees it happening again, brings         it
forward as MIS and also notes previous instance.
I think stiupulating a time limit by which matters must be reported places an
unnecessary burden on the complainant and could generally depreciate
misconduct in science on a campus ("doesn't matter if you didn't get caught
then").   The older an allegation is, the more one would wonder why the long
wait, but there are ways of dealing with those, and, perhaps unfortunately,
some of the reasons can't matter anyway--the motives of the claimant are
immaterial as long as the allegation is in good faith  ("getting even" by
reporting an actual instance of MIS).

On the other hand, there are practical limitations:  most (there are
exceptions) records are purged 3 years after the conclusion of a funded
project.  It is possible that information would no longer be available upon
which to base a determination, simply because of normal record purging (which
is different from records having been "disappeared!" ).  Our procedures
include lack of credible evidence as a reason for determining not to pursue a
matter:  "sufficient credibile evidence is lacking to make a determination
that misconduct in science may have occurred and that an Investigation is
warranted, in which case the respondent is considered not culpable."   The
more elapsed time between event and reporting of event, the harder it is to
verify the circumstances of the event -- but it is incumbent upon the
institution to examine those with the same care as fresh events.

................................................................
Celia S. Walker, Director
Office of Regulatory Compliance
608 University Services Center
Colorado State University
Ft. Collins, CO  80523
TEL:970/491-1563         FAX:970/491-1958
INTERNET:xxxxxx@vines.colostate.edu