Sten grillner 's group at the karolinska institute in stockholm has therefore spent many years studying lampreys , in order to gain insights about vertebrate nerves .
Evidence gathered at the scene of the crime-including gabc k 's british-made sten gun , and british explosives , fuses , and bullet casings-made it clear the perpetrators were commandos parachuted in from abroad , rather than the product of a homegrown resistance movement .