We had a person delete a reqs folder, that's a problem in itself. But the issue I have is, we do not know who did it and I am trying to find out if there is a history any where for that type of activity.
You can get the deletion history from
1) AUDIT_LOG and AUDIT_PROPERTIES table. These table contins historical information.
2) If you have log enabled of debug level, you can find out the person who deleted the req and when.
The audit* tables only keep changes to fields you have specificed require historical data. They won't tell you if a test, requirement, or defect has been deleted nor who deleted it.
The logs will give you who and when -- however, it's like finding a needle in a haystack. First you need to know what you are looking for (test id, Defect id, etc) and then you need to narrow it down to a day time frame.
Better to turn off deletes for everyone. For Tests and Requirements then give them a trash folder and have the users move junk to the folder. For Defects -- I am sorry --- they shouldn't be delete no matter what. If they are no longer valid then the user needs put a reason in the defect and close it.