The current state of technological development associated with the decreased cost to access information has made public opinion become increasingly more active and important in defining criminaljudicial policy and decisions. The issue is whether this influence beneficiates the development of the legislative and judicial systems or if it is negatively inducing decisions that are incoherent with the constitutions. The objective of this study is to analyze the cost and benefits of public opinion on judicial policies and decisions through a case study of the prosecution of homicides in traffic on public roads in the Brazilian judicial system. Recent media coverage and public opinion manifestations have led Brazilian judges to create a doubt between eventual intention of murder and manslaughter in homicide crimes in traffic on public roads. Thus, the severity of these decisions and the compatibility with the Brazilian criminal law will be verified through this case study.