This study looks at one hundred cases of siblicide committed across the United States. Cases are analyzed for criminality patterns which are used by the author to determine offender typologies. The goal of this research is to determine why this type of crime is committed, this question is answered by analyzing offenders and the crimes themselves. This research is important because this type of crime dates back to biblical times with the story of Cane and Able, and it has remained a problem within society. Though this type of crime has been investigated in the past it is necessary to reanalyze similar crimes to remain current on data, over time society changes and with it so does the method and rational for crime. By analyzing crimes of this nature and identifying typologies it will begin to paint a picture of why such crimes occur and can assist those who investigate similar crimes today. To conduct this research one hundred cases of siblicide were collected from across the United States in qualitative form. These cases were found online from reputable news sources that reported on them. They were then compiled into a grid and broken down by date, state, ethnicity and age of offenders and victims. The grid also contains data on weapon used, rational for killing, and a description of the crime that occurred. After the cases were collected, the author picked through the details and began to identify patterns within the cases. From these cases typologies can be created based on similar patterns between the cases. Once typologies are made the data is looked at through a theoretical lens using strain theory to determine if stress could potentially be a leading cause in this crime. The data compiled for this research is still being examined and a conclusion has not yet been made, though the author does expect to see a high level of stressors for those who commit this type of crime. This is expected due to the displacement that can occur with the presence of a sibling. It is expected that in a number of cases factors such as conflict, jealousy and financial stress will be the root cause of the violence that occurs. As for cases of younger children involved in cases the author expects to see a high level of accidental shootings paired with parental neglect. In conclusion this research will shed more light on a crime that has been occurring for thousands of years, and will allow one to understand siblicide in a modern context, by discussing why and how it occurs in today’s society. If it is found that stressor are not the predominant cause of this type of crime it would mean that there is a separate issue to address within this type of crime, and this research would help to identify what it is that truly causes siblicide to occur.