These include the relationship between the risk of discovery and the police crime clearance rate, the definition of the concept risk of discovery, and a method for calculating risk of discovery. The report, in examining risk of discovery, distinguishes between discovery of the crime as the primary reason for arrest and discovery when an arrestee is linked to crimes other than those for which arrested. In examining files on 23,000 burglaries cleared in 1986, researchers found that barely 10 percent of burglaries were closed, and the risk of discovery was 7 to 9 percent. Discovery of burglary as the primary crime for arrest occurred in from 2 to 4 percent of the cases. Overall, in 1986, a thief in Sweden had a 2 to 9 percent risk of being linked to the crime at anytime in his criminal career. For theft from vehicles, the risk was 3 to 5 percent, and for assault, 5 to 11 percent. For drunken driving, clearance rates were nearly 100 percent of incidents reported, since police generally are the discoverers. However, considering the likelihood that such incidents go unreported, the percentage is calculated at .3 to .5 percent. Study data are provided.