The core symptoms of autism spectrum disorders (ASD) are likely to affect interactions between law enforcement officers and persons with ASD. If law enforcement officers are not trained to identify and appropriately respond to persons with ASD, it is possible that officers may exacerbate a situation, resulting in unnecessary trauma, injury, or fatality. The purpose of the current study was to evaluate the effectiveness of a method of law enforcement training on persons with ASD. A total of 82 law enforcement officers participated in this randomized, waitlist-controlled, between-groups study. The results revealed significant differences in change scores between groups, with the training group scoring considerably better than the control group at posttest. Subsequently, the control group completed training and likewise showed significant improvement. However, despite the significant gains in knowledge following training, posttests scores for participants in both groups did not indicate mastery of the training material. The implications of these findings are discussed. (Contains 3 figures.)