Your description suggests that you need to review the data model. Whatever approach you take comes with its own set of issues and constraints, and part of the art of design is choosing which set of issues you are most willing to live with. However, duplicating a Person record is probably not the best way to address this need. You could consider:
1. A separate table of Titles, and a join table to link titles to people with from… and to… dates to delineate current titles from past titles.
2. Simply changing the title in the person record, but logging the change somehow (e.g. using NightWing's UltraLog, or similar) so as to maintain the person's history.
3. Whichever method you use, making sure that where changeable data is deployed (such as in event participation) it is posted by auto-enter or lookup, not just referenced, to make sure past records are not changed when data changes. (Note: this is really just a variation on the common "purchase price" issue in an invoice.)
4. If you decide to stick with your duplicate person method, then you could create an additional key field to link the two (or three, or four, or more) versions of the same person and then build your report based on that field rather than standard uniqueID field.
5. No doubt there are many other ways you could approach this requirement, but that will do for now.
A simple approach in this case may be an auto-enter field in the Event table that populates with the title of the user/lecturer. However, as per keywords, a separate table of Titles may be of value regardless of your
eventual approach. In this case, the auto-enter field in the Event table may populate with the TitleUUID instead of the actual title.
keywords is right, you don't duplicate a person record just because he changed title.
There is an easy solution to your problem - although it is not very pure from a data modelling pov: store the title in the attendance join table as well, together with the professor's ID. This way you can have actual data (read: title) in the people database and the attendance table itself keeps track of what the title was when they attended.