Center for Problem-Oriented Policing

Sting Operations According to Crime Targeted

Sting operations vary in their use of deceptive techniques, depending on the specific crime type targeted. The following summary of sting operations’ methods, durations, costs, and outcomes according to crime targeted is drawn from various professional magazines, government-sponsored reports and evaluations, and a small number of scientific studies. It is likely that there have been many sting operations about which nothing has been published, so there may be a bias toward reporting only stings that were deemed successful, a bias likely aided by positive media coverage when the media itself was enlisted to help in the operations.

Fencing and Stolen Property

The overwhelming technique used in penetrating fencing operations is the storefront. One of the major problems of using storefronts is the expense in setting up the store, and the need for “buy” money to provide goods for sale. The sources of these often considerable needs for funds are provided from state and federal grants, and sometimes from local businesses that are targets of theft, such as local car dealerships. Federal grants often require working closely with federal law enforcement investigators such as the FBI. Reports of operations vary in the extent to which they consider the outcomes successful, though the main focus is usually on cost-effectiveness because of the high costs of setting up and implementing these stings. The measures of this are particularly difficult to pin down, since they depend on how long the operation continues (since police recover more goods, but also need more buy money). The rate of return on the dollar therefore is usually computed according to the value of goods retrieved and returned to their rightful owners, as against the amount expended to set up the operation. However, this accounting often does not include the officer time used in the sting, so the results may be misleading. One study that included personnel costs reported that it cost 2.5 cents of buy money for every dollar recovered.9 Another reported that it cost roughly 10 cents for every dollar retrieved. 10

The more scientifically designed studies tend to regard claimed successes as “questionable” as far as prevention or reduction in fencing of stolen goods is concerned. 11 However, two such studies12 did report a decrease in the specific crime targeted. The most persuasive measure of a sting’s success—and most widely reported—are the mass arrests that follow almost every sting and the extremely high conviction rates of around 90 percent. Although some researchers have questioned this high conviction rate (since factors that could affect conviction rates such as arrest rates, plea negotiations, and decisions not to prosecute are often ignored in computing conviction rates), it is nevertheless reasonable to conclude that the conviction rates of cases that go to trial are very high.

There is far more research available on storefront operations targeted at fencing activities than on any other type of sting. The scientific quality of these studies is on the whole higher than for other types of stings, most of which are descriptive and assume that the outcome of arrest is self- evident of a sting’s success.

† In a study that used frequent stings against prostitution, it was found that prostitutes who were arrested returned to the streets after a brief period, which left the recurring problem unsolved ( San Bernadino County (Calif.) Sheriff’s Department,1993 [Full text]).

Drug Dealing

The most common technique for sting operations directed at drug dealing in various environments is the reverse sting “buy and bust” (an officer pretends to be a drug dealer and sells to an unsuspecting customer). However, in contrast to storefront stings, police more often use drug stings in conjunction with other responses such as sweeps, crackdowns, and beefed-up patrols in known dealing locations. Those operations that combine stings with other responses are most often rated as “successful.” While it is probably a good idea to combine stings with other operations targeted at reducing drug dealing (see Problem-Specific Guide No. 31, The Problem of Drug Dealing in Open-Air Markets), this practice makes it difficult for researchers to assess whether an operation’s success was a result of the sting itself, or of the other responses used. Many studies deem the sting operation “successful” if it results in massive arrests. In general, the conviction rates range up to 50 percent of arrestees 13, considerably lower than for storefront operations.

Some drug stings, especially those lasting a longer period, result in short-term reductions not only of the targeted crime, but also of other crimes such as robbery. On the other hand, one study found that while significant reductions in drug trafficking were achieved, there was some evidence that it was displaced to other locations that were not part of the sting.14 In fact, drug dealers were forced underground, which made it more difficult to maintain a buy-and-bust operation. In sum, while stings clearly have short-term effects on drug dealing, no scientific studies have demonstrated a long-term effect. Finally, because sting operations are expensive, it is necessary to assess whether the overall cost of these operations is worth it. One study found that it took 802 officer hours per violent crime deterred,15 another that it took 6.6 officer hours per arrest.16

Sales of Alcohol and Tobacco to Minors

Operations targeting sales of alcohol and tobacco to minors use juveniles as minor decoys to enter stores to buy liquor or tobacco. One operation used detectives to follow up some time after juveniles had made the purchase. The duration of the stings ranges from days to years. One scientific study that investigated the effects of the California STAKE Act †† found a 42 percent reduction in access to tobacco by minors after a publicized sting operation. However, juvenile access to tobacco began to increase to previous levels after one year. Two other similar studies of illegal liquor sales to minors produced many arrests, and illegal sales dropped by some 20 percent for the first year. However, another scientific study reported that illegal sales increased after a follow-up by detectives once the sting operation had ended.17

† New York City’s Operation “Pressure Point” resulted in 14,000 arrests after 17 months and a 52 percent reduction in robbery after two years (Zimmer, 1990).

†† The California STAKE Act of 1994 established an intensive statewide program to reduce illegal sales of tobacco. Implementing the act required an initial survey of retail stores to establish how widespread the problem was and intensive enforcement programs, and included scientific evaluations of the interventions that included sting operations (minors acting as police surrogates).


Female decoys or plainclothes detectives are typically used in prostitution operations. These stings always result in many arrests and good publicity, but researchers have concluded that they have no overall effect on clients.18 However, a benefit of vice stings is that they also help police serve numerous outstanding warrants for offenders wanted for other types of crime. An FBI sting took over a credit card processing company and identified those who had used credit cards to pay for sex. It then processed payments to and from the brothels over a three-year period. This resulted in snagging $100,000 in bribes of local police and the closing of 18 parlors.19 Few of the descriptive studies reported the length of the stings, which suggests that police used them in conjunction with the popular use of vice sweeps as a response to persistent prostitution (see Problem-Specific Guide No. 2, Street Prostitution).

Vehicle-Related Crime


Although random stops for license, registration, or breathalyzer checks are common in police practice, there are few actual studies of their effectiveness (see, e.g., Problem-Specific Guide No. 3, Speeding in Residential Areas; Problem-Specific Guide No. 36, Drunk Driving). There are studies demonstrating the effectiveness of random breath tests on drunk driving; although random stops are not necessarily stings, they do have a “gotcha” element. One sting used police in plainclothes in the courtroom to inform uniformed officers waiting outside for those whose license was suspended. The officers then arrested the offenders if they tried to drive away. The scientific study reporting this sting demonstrated a reduction in collisions and hit-and-run injuries over a two-year period20 during and following the sting.

Car Theft

The most common sting technique used against car theft or theft from cars is the bait or decoy vehicle. Although some successful uses of decoy vehicles have been reported in the United Kingdom, their effects on car theft reduction have been only temporary.21 (See Problem-Specific Guide No. 10, Thefts of and From Cars in Parking Facilities; Problem-Specific Guide No. 46, Thefts of and From Cars on Residential Streets and Driveways). Reports of U.S. sting programs using bait cars suggest similar results.

Street Racing

Police have parked decoy police cars at the scene of street racing events, with the aim of deterring street racers. However, their effectiveness is unknown, and leaving them unattended also invites vandalism (See Problem-Specific Guide No. 28, Street Racing).

Fraud and Corruption

The fraud and corruption category includes an assortment of reports on undercover officers investigating a variety of such cases. One operation investigated 38 car body shops concerning the submission of fraudulent insurance claims for preexisting damage of a car, resulting in many arrests.22 Operation Greylord uncovered judicial bribery and corruption, resulting in scores of arrests and extensive congressional testimony. Consumer and immigration fraud were also uncovered by sting operations that police used primarily as tools of investigation over months and years. All operations resulted in multiple arrests and convictions. 23

† In a complex project to reduce car theft the Williams Lake (British Columbia) Royal Canadian Mounted Police used bait cars along with other responses, including: considerable community and business involvement, intensive enforcement, and considerable publicity. In the six months of the study, car theft dramatically declined, but there is no way to determine whether this reduction was due to the bait cars or other responses used. ( Royal Canadian Mounted Police, 1997 [Full text]).

Child Pornography and Pedophiles

The Internet offers police an excellent medium for undercover operations, and they have used it considerably to track down and snare would-be child molesters or child pornographers. Methods used are for officers to enter chat rooms and pose as a child seeking excitement; setting up false web sites offering illegal pornography; and using a well-publicized Internet sting operation to create the impression that the Internet is a risky place for sexual predators, and that their hidden identities can be tracked down. 24 The latter use of a sting operation differs from other uses described above because it is not primarily oriented to investigating a complex crime resulting in arrests, but rather to deal with the problem in a wider perspective by creating an uncertain atmosphere and thus deter potential predators. Arrests, therefore, are not the measure of success. Unfortunately, there are no scientific studies that have used as a measure of success how many people have been deterred from seeking child pornography or trying to contact children through teen chat rooms as a result of well-publicized sting operations25 (see also Response Guide No. 5, Crime Prevention Publicity Campaigns; Problem-Specific Guide No. 41, Child Pornography on the Internet).

† Internet stings that aim at tracking down Internet users require highly trained officers in the Internet’s technical aspects, as well as Internet service providers’ cooperation. However, a reasonably competent Internet user can put up a false web site, and it takes little skill to enter a teen chat room.