FLIPPING A WITNESS: Can it be Abused?

According to Merriam-Webster Dictionary, Flip means: to cause or persuade (a witness) to cooperate in prosecuting a criminal case against an associate.

It's regularly used within the American Judicial System, by federal, state, and county prosecutors. Certainly, it has its place in persuading a lesser criminal to offer information on a more dangerous or corrupt individual. In white collar crimes, it's an effective tool--within limits.

White collar crime focuses mainly on non-violent crimes. But, what happens when violent criminals are being "flipped?" What abuses might occur?

Has the Boston US Attorney's Office abused this practice? When 5 criminals--John Morris, John Martorano, Steve Flemmi, Pat Nee, Kevin Weeks (and more...) whose combined body count is more than 100 souls and federal crimes exorbitant, are given absolution in order to incarcerate an individual whose crimes are less--we have to step back and ask how this is just? Have the scales of "justice," in such cases, been altered? Have judges turned a blind eye to such abuses? And, what is the danger to every citizen if it is so? Not only does this practice allow the possibility of innocent citizens being accused of a crime, but it puts individuals and families at risk--might your neighbor be a murderer who has been absolved of his crime because he offered "damning information" on an associate? (Doesn't seem to matter if the "damning information" is true in many cases.)

Should prosecutors and judges be held accountable for such abuses?