Limiting duplicate records in secondary tables?

I have a report in CR2010 that links multiple tables. One of the linked tables has a many-to-one relationship with the primary table. I need a way to say, in effect, "Only the record with the latest date from the secondary table", thus pruning the earlier dated records. Con someone please provide a few pointers and/or some articles I can read to assist in this? Thanks!!

ETA: What's happening is that, because of the multiple records associated with each primary record, I'm getting multiple identical details, with only the one field from the other table different. I need to only have ONE detail line that is limited to that latest secondary table record.