What police executives came to learn in the 1990s was that police could reduce crime, if they acted proactively. Waiting until someone got shot and then trying to convince witnesses to testify was hopeless. Targeting hot spots with aggressive patrol, and utilizing stop-and-frisk tactics to get guns and drugs off the street, did not require civilian witnesses to put themselves in harm's way, but they made it risky to carry guns and drugs. When guns and drugs move off the streetscape, in turn, the risk of violent confrontations declines.