We study whether economic incentives matter for crime in a novel way, through study of expensive precious metal thefts by thieves stealing catalytic converters. We combine sharp, plausibly exogenous variation in the prices of precious metals embedded in converters with newly assembled U.S. data and multiple research designs. We show that phenomenally fast increases in precious metal prices generated a sizeable and rapid rise in auto-part thefts, while subsequent price declines and policy responses quickly reversed this pattern. The resulting boom-and-bust dynamics provide clean evidence that both demand- and supply-side economic forces shape property crime and inform targeted deterrence policies.