Informants are the foot soldiers in the government’s war on drugs. By some estimates, up to eighty per cent of all drug cases in America involve them, often in active roles like Hoffman’s. For police departments facing budget woes, untrained C.I.s provide an inexpensive way to outsource the work of undercover officers. “The system makes it cheap and easy to use informants, as opposed to other, less risky but more cumbersome approaches,” says Alexandra Natapoff, a professor at Loyola Law School in Los Angeles and a leading expert on informants. “There are fewer procedures in place and fewer institutional checks on their use.” Often, deploying informants involves no paperwork and no institutional oversight, let alone lawyers, judges, or public scrutiny; their use is necessarily shrouded in secrecy.