In the UK there is a fictional police series called 'Waking the Dead'. This is about a cold case squad who re-examines old unsolved crimes when new evidence or technologies become available. Needless to say the team have a whizz kid on the forensic side who is equipped with the latest technology. They have a technical advisor for the series so all the science reflects reality despite being a fictional series.
In the latest programme they were faced without a DNA match for a rape sample. However after a great argument about civil rights, they widened the DNA search on the database to find someone who could be a close relative of the rapist. After a bit of unlawful breaking in to houses without warrants, Bingo they were able to deduce were the rapist lived!
It's a great series especially if you like gory scenes cutting up bodies etc Yuk!
http://www.bbc.co.uk/iplayer/episode/b00mtv1s/Waking_the_Dead_Series_8_End_of_the_Night_Part_2/