The following analyses uses the Federal Bureau of Investigation’s (FBI) Supplementary Homicide Report (SHR) data from 1984 to 2009 to examine factors that predict whether a homicide will be cleared or not (N=439,542). Two theories inform the current study: 1) Black’s theory of law (discretionary variables) proposes that characteristics of the victim, such as age or race, influence how diligently police work to solve a homicide; and 2) non-discretionary theories propose that characteristics of the homicide act, such as geographic location and weapon use, are more important to the solvability of a homicide. Preliminary analyses of clearance rates indicate decreasing rates from 1984-2004, and increasing rates from 2004-2009; therefore, separate analyses are performed for each trend.
Results indicate that firearm use, unknown weapons, males, minority victims, population size, and western regions predict lower clearance rates. However, predicted probabilities analysis provide a more complete picture of the relative importance of each variable. Most variables support non-discretionary theories of crime, where aspects of the homicide itself determine its solvability. Theoretical implications are discussed alongside directions for future research oriented toward more practical analyses of homicide clearance rates and police practices