A couple of days ago I posted a link to an article discussing prosecutorial discretion and what The New York Times called a "prosecutor's inherent conflict of interest" in cases that involve the possible indictment of police officers. I also posted a link to a discussion in the Legal Ethics Forum on whether the prosecutor in Ferguson, Missouri had a conflict of interest.
As part of that discussion, many are calling for the use of special prosecutors in cases involving police officers. The New York Times' Room for Debate has published five short comments on this issue here.