This paper describes a problem-oriented policing project, extending over a period of more than two years, which was designed to reduce thefts from cars parked in the center city of Charlotte, North Carolina. A progressive tightening of focus led to a detailed analysis of the risks of theft, and the associated security features, in the 39 decks and 167 surface lots in the center city. This analysis showed (1) that risks of theft were much greater in lots than in decks and (2) that higher risks of theft in lots were associated with inadequate fencing, poor lighting, and the absence of attendants. These data played an important part in obtaining the agreement of lot owners and operators to make security improvements. Before most of these improvements had been made, however, thefts in the lots began to decline, possibly as the result of more focused patrolling by police and security personnel. The paper concludes with a discussion of the difficulties encountered by police in undertaking problem-oriented projects, and of ways to help them meet these difficulties.