Dogs have been trained to sniff out bedbugs.
We know they're good at detecting bombs. They're used to find drugs (sometimes with mixed results). They can detect foods hidden in travelers' luggage. And their noses can lead them to missing persons and those who've been buried in earthquakes and other natural disasters.
There's even evidence that they can help detect cancers in humans.
Now there's word from Sweden of a police dog who has been trained to help hunt down sex offenders by sniffing out evidence of semen at crime scenes.
Rapports Opus (the dog) tracked down the evidence at a Swedish park where a man allegedly sexually assaulted a woman. The Local (Sweden's News in English) reports that "the dog found traces of semen on the scene of the crime and after being sent for analysis these were found to match the [suspect's] DNA."
As the Connecticut Police Work Dog Association has previously reported, canines have also helped pinpoint evidence at scenes of sexual assaults in the U.S.