MATCH, INDEX, LOOKUP - Help!

[RobPot]

Hi all,
I have two worksheets 'Crime report' and 'CSI report' where the common link is the Unique Reference Number. However there are more crime reports than CSI reports.
What I'm trying to get to is a third worksheet where the URNs are shown where they have appeared on both previous sheets - I'm guessing that I can then pull any additional data I need using an OFFSET formula.
I tried:
=MATCH('Crime report'!D:D,'CSI report'!D:D,0)
but that only returns the cell reference rather than the number and I can't work out what to do next.
Just to be clearer the data is structured with each report across a row with columns headings such as URN, date, address etc. in the above formula the URN is in column D on each sheet.

Any ideas?
Many thanks

Robert