We conducted the present study in order to contribute to scientific crime investigations by combining academic outcomes with the scene of actual investigations through studying serial sex offender profiling and profiling systems. We analyzed general characteristics of serial sex offenders and geographical characteristics of serial sex offenses, differentiated between different types of serial sex offenders, investigated the current state of Korean offender profiling system and its problems, and discussed policy implications for the effective profiling system. The results of the present study is as follows. Most of serial sex offenders attacked a female stranger to them, typically by breaking into her house, followed by a surprise attack. The victim characteristics, approaching methods, and the use of weapon were related to high within-offender consistency and high between-offender variability, which can be effectively used for case linkage analysis. However, sexual behaviors and post-offense behaviors were related to low within-offender consistency and low between-offender variability. The interpersonally-intimate type and violent type of serial sex offenders displayed highly opportunistic nature at the time of crime commission. On the other hand, the controlling type of offenders, who consisted of almost half of the serial sex offenders, displayed a high level of criminal sophistication, committing behaviors such as preparing binding instruments and/or weapons before the offense, wearing hats or gloves and ejaculating outside the body to avoid apprehension, and stealing from the victim or threatening the victim not to report after the offense. In terms of the socio-psychological characteristics of the serial sex offenders, they turned out to be relatively young and mostly single at the time of the offense. Organized offenders committed their offenses at the zone apart from their residence, whereas disorganized offenders, who were mostly impulsive and alcoholic, committed their offenses near their residence. The problems of Korean offender profiling system are as follows. First, the "profilers" are appointed to the positions which are barely related to their expertise. Second, they find it difficult to concentrate on developing crime analysis techniques because of their excessive work load and relatively low ranks. Third, the chief of the investigation department, who often lacks of knowledge of offender profiling, decides the necessity of offender profiling, which sometimes leads to critical misjudgement. Fourth, the investigation files of crime offenses committed across the country are not collected and analyzed together, which leads to the possible failure of serial case linkage. Fifth, the opportunity of participation is often limited for the profilers as their roles for crime investigation are often underestimated. Sixth, because of this lack of actual crime scene investigation experiences, the profilers often find it difficult to superintend operations of investigators. Seventh, the lack of trust between the profiler and their chief of the investigation department who has limited knowledge of the importance and the accurate application of offender profiling often leads to practical problems such as work order of a remote possibility. Eighth, although profilers were employed without being tested on their knowledge of criminal law and general police work, they are still not fully trained on these matters. Ninth, the opportunity of specialization education for profilers and investigators is severely limited both in terms of quantity and quality. Finally, the investigators who are accustomed to the traditional investigative techniques may refuse to cooperate with profilers, which may create severe problems. In order to resolve these issues, various improvements are required. The specific and practical solutions are required to maximize job contentment and commitment. The central investigative team should be constructed to effectively distribute duties including crime investigation, analysis and research. The cooperative system with foreign countries, especially Asian countries, should be developed for sharing international crime data. The profiling techniques are important not only for profilers but also for all police officers; therefore, all of them should trained on these techniques by curricula consisting of both general police duties and specialized methods of criminal profiling. Also, the crime analysis checklist for SCAS should be applied to all cases and it should be profilers themselves who decides the necessity of offender profiling techniques for the present case.