snipped from above article:

New DNA technique could help reopen thousands of 'cold cases'

Called "DNA Boost", the new technique, developed by the FSS, allows scientists to create profiles from "mixed" samples, which contain genetic information from two or more people found on the same surface
"In the past it has been very difficult to unscramble these samples," said Dr Mark Pearse, from the FSS, "which means they cannot then be searched for in the DNA database."

Now, however, the FSS has developed computer software capable of matching "pairs" of this scrambled data together, creating possible DNA matches.

These can then be fed into the database, which currently contains the details of about four million people, identifying potential suspects.