Gloria Killian was freed after years behind bars for a robbery-murder plot in which she was utterly innocent. Unfortunately, this isn't a story about justice being served. It's a story about yet another prosecutor intentionally concealing evidence to dupe a jury into conviction.
In Killian's case, the conceal evidence showed the state's star witness traded leniency in his own case for testimony spreading blame to Killian. The hired witness agreed, and happily claimed under oath (to save his own skin) that Killian – whom he'd never actually met – masterminded the whole thing. Sigh. Normally, when a witness is paid for testimony – in money, or in freedom – the jury gets to consider how the fact and extent of payment impacts the jury's decision what it will believe. By hiding the fact the "star witness" was a paid rat, the State bolstered his credibility and prevented the jury from understanding his real motive to testify. Under our system, when a witness informs the prosecutor "I even lied my ass off on the stand for you people", the wrongly convicted don't automatically go free. Instead, the reports I've seen suggest the letter ends up in a drawer.
In the U.K., I understand the government doesn't have barristers on salary. The government's solicitors engage barristers to try cases from a pool of available barristers who try criminal matters, and the barristers who work on a particular case may have worked for the defense the prior week and may work for the government the next month. They have no career need to get convictions, and their perspective on their cases has the breadth of seeing both sides. Their objective isn't to advance the office of the prosecutor. Ideally, the United States would not have prosecutors bent on getting convictions of innocents in order to improve their scorecards, but our system is broken. The convict-at-all-costs culture of many prosecutors' offices has been noted before.
The American Bar Association's rules applicable to prosecutors – widely adopted by state bar organizations – explicitly state in Standard 3-1.2(c) that "The duty of the prosecutor is to seek justice, not merely to convict." But have you ever heard of anyone being promoted in a district attorney's office for seeking justice? It's the conviction rate you see measured. And you get what you pay for. So if you measure nothing but convictions, what do you expect?
Let's stop paying for empty convictions, and start motivating people to get the right people behind bars. Or – and here's an idea – keeping people from ending up offenders.