Throughout history, individuals who sexually victimize children have frequented the places where children gather. In addition, offenders have used technological capabilities, such as automobiles and cameras, to assist their sexual interests and behavior. However, today the technological advancement of the computer, specifically the Internet, has offered offenders a new point of contact with children. To investigate child sexual exploitation cases involving computers requires knowledge of the technical, legal, and behavioral aspects of computer use. This article focuses on the behavioral aspects of both the offender and the victim. Offenders using computers to sexually exploit children usually fall into two categories: the situational offender or dabbler and the preferential offender. The preferential sex offenders, also known as the pedophile, are the primary sexual exploiters of children. This offender has a wide variety of deviant sexual interests with a definite preference for children. Investigations must recognize and utilize the highly predictable sexual behavior patterns of preferential sex offenders. Identified behaviors for preferential sex offenders are divided into four categories: (1) long-term and persistent pattern of behavior; (2) specific sexual interests; (3) well-developed techniques; and (4) fantasy-driven behavior. Knowing the kind of offender with whom one is dealing can go a long way in determining investigative strategy. Once there is an understanding of the offender, there becomes a better understanding of the appeal of a computer. Offenders use computers to organize their collections, correspondence, and fantasy material. Many offenders are drawn to the Internet and other online activity as a way to communicate and validate their interests and behavior. In addition, offenders have the capability through online services to transfer, manipulate, and even create child pornography. With the capabilities of the computer, offenders can use the computer to troll for and communicate with potential victims with minimal risk of being identified. A child can be indirectly victimized through conversation and the transfer of sexually explicit information and material and can be evaluated for possible face-to-face contact and direct victimization. Investigators must be alert to the fact that any offender with the intelligence, economic means, or employment access could be using a computer, but preferential sex offenders are highly likely to do so.