A prosecutor is viewed by the public as a powerful law enforcement official whose responsibility is to convict guilty people of crimes. But not everybody understands that a prosecutor’s function is not only to win convictions of law-breakers. A prosecutor is a quasi-judicial official who has a duty to promote justice to the entire community, including those people charged with crimes. Indeed, an overriding function of a prosecutor is to ensure that innocent people not get convicted and punished.
A prosecutor is constitutionally and ethically mandated to promote justice. The prosecutor is even considered a "Minister of Justice" who has a constitutional, statutory, and ethical duty to ensure that a defendant is convicted on the basis of reliable evidence in proceedings that are fair. Nevertheless, some prosecutors deviate from these rules and engage in conduct that distorts the fact-finding process and produces erroneous convictions. Indeed, if a prosecutor is motivated to zealously win a conviction by any means, and engages in conduct that either intentionally or carelessly undermines the integrity of the fact-finding process, the prosecutor inescapably will bring about the conviction of a defendant who is actually innocent.
Bennett L. Gershman, The Prosecutor’s Contribution to Wrongful Convictions, in Examining Wrongful Convictions: Stepping Back, Moving Forward 109 (Allison D. Redlich et al., eds. 2014), http://digitalcommons.pace.edu/lawfaculty/962/.