Prosecutorial discretion has historically been the subject of acute scrutiny for both its breadth and unfettered authority in the criminal justice system. In the area of environmental law, this discretion is especially impactful given that the environmental regulatory system does little to distinguish between civil and criminal enforcement. Considering these concerns surrounding broad discretion and the vague regulatory system, this research intends to contextualize how environmental prosecutors make charging decisions. Specifically, this study analyzes a series of civil and criminal pollution cases across the administrations of President Obama and President Trump; the purpose of this design is to investigate the factors that compel a prosecutor to pursue a criminal charge and furthermore, determine the differences between civil and criminal enforcement. The results suggest that, across both presidential administrations, prosecutors reserve criminal enforcement for cases that include significant environmental harm or deceptive conduct. Moreover, civil enforcement is typically reserved for defendants that do not commit knowing or willful violations. However, when analyzing the data between presidential administrations, the results suggest that, in order for a case to have been criminally prosecuted during the Trump administration, the violation had to be especially severe. Ultimately these findings imply that prosecutors have coherent patterns to their behavior and that the political administration in power can affect a prosecutor’s decision to pursue a case civilly or criminally.