Results indicated that OC was generally effective at reducing aggressiveness among already aggressive suspects but it actually increased aggressiveness among suspects who were initially non-aggressive. Overall, OC was effective against most suspects, except suspects who were under the influence of drugs, violent suspects, minority suspects, and suspects who were warned before being exposed to OC. Although the vast majority of officers were satisfied with OCs performance during use-of-force encounters, officers with more experience were more likely to report OC as being effective than their counterparts with less experience. The analysis suggests that officer satisfaction was most strongly linked to whether or not suspects became incapacitated, followed by whether or not OC eased the arrest. Data was drawn from all 26 Dutch police forces on incidents involving OC use between June 2001 and December 2002. For each OC use, officers reported the use on a dedicated use-of-pepper spray report form which included instructions to rate the effectiveness of the OC use. Substitute prosecutors who interviewed arrested suspects and arrested suspects who had been sprayed were also asked to complete the forms. A total of 1,882 use-of-pepper spray forms were completed by officers, another 1,227 forms were completed by substitute prosecutors, and 8 forms were completed by suspects. Overall, the data related to 1,603 incidents in which OC was used on a suspect. Statistical data analysis involved the use of the ordered logit model (OLM). Future research should focus on discovering the types of drugs most strongly associated with OC failure to incapacitate. Tables, notes, references