Mental retardation refers to a serious inability to learn and perform well in social situations. There are four levels of retardation -mildly retarded, moderately retarded, severely retarded, and profoundly retarded. The typical mentally retarded offender is male, in his late 20's or early 30's, a dropout with educational skills at the second or third grade level, from a low socioeconomic minority, in an unskilled or low-skilled occupation, and mildly retarded. When an officer evaluates a situation with a person who may be mentally retarded, he or she should consider appearance, communication, adaptive behavior, and educational background. Many offenders in this category are street-wise despite their handicap. The retarded person will respond according to his fears and the degree of his retardation. Interviewing a retarded person is difficult and calls for patience. The question of rights will be important during the investigation. Missing person cases are common situations in which the officer will encounter retarded persons. Parents of a missing retarded child understandably become excited and panic quickly because they are fully aware of their child's inabilities. The officer should try to alleviate their distress. One table is included. A discussion guide and study questions are provided.