"Derrick" is unbeatable. He's right in 98.8 percent of all cases, the kind of accuracy only machines can achieve. But Derrick is no machine. He's part of an elite group of sewer rats currently being trained in Rotterdam to sniff out drugs, gunpowder or traces of other substances that cling to someone after they've committed a crime.
Shooting a gun leaves behind gunshot residue that until now could only be detected in a costly laboratory. Dutch police, under pressure to save money, now see Derrick and his four classmates as a cheaper and faster option than traditional science. The project's potential savings has won it the support of the police's "innovation manager."