The current article addresses the ongoing debate about whether individuals can perform as well as actuarial techniques when confronted with real world, consequential decisions. A single experiment tested the ability of participants (N=215) and an actuarial technique to accurately predict the residential locations of serial offenders based on information about where their crimes were committed. Results indicated that participants introduced to a ‘Circle’ or ‘Decay’ heuristic showed a significant improvement in the accuracy of predictions, and that their post-training performance did not differ significantly from the predictions of one leading actuarial technique. Further analysis of individual performances indicated that approximately 50% of participants used appropriate heuristics that typically led to accurate predictions even before they received training, while nearly 75% improved their predictive accuracy once introduced to either of the two heuristics. Several possible explanations for participants’ accurate performances are discussed and the practical implications for police investigations are highlighted. Copyright # 2004 John Wiley & Sons, Ltd.