Intelligence, consisting of critical products that facilitate law enforcement decision-making, is a crucial component and tool in the criminal justice system. However, the ways in which intelligence is gathered and used has gone largely unevaluated, particularly at the local level of law enforcement. This thesis begins to address the sparsity of literature by investigating the Intelligence Officer function in the Phoenix Police Department. More specifically, this study explores their roles; perceptions on information they are gathering, namely reliability and validity; and their effectiveness in terms of both intelligence and case successes. Different aspects of roles and perceptions are also examined in terms of their ability to predict these outcomes. Data reflect a 22-month sample of officer reports from the Phoenix Police Department Intelligence Officer Program. Descriptive analyses suggest that Intelligence Officers typically work specific cases with varied and different natures of crime. Generally, officers seem to be confident in the information they collect in terms of reliability and validity, and also appear to be relatively successful in achieving both broad intelligence successes and more tangible case successes. However, the relationships between role and perception variables and results vary in terms of both impact and significance for each type of success. Future research is required to better understand these relationships and to continue building a foundation of knowledge on Intelligence Officer effectiveness, so their impact can be optimized.