More US prisoners were exonerated of crimes that they did not commit in 2014 than in any year since records began in 1989, indicating new resolve on the part of prosecutors and law enforcement to tackle the scourge of wrongful convictions across America.



Some 125 inmates were exonerated and released last year, marking the first time that the number has risen above 100 in a single 12-month period. In 2013, the total number of exonerations was 91.

The record number, as recorded by the National Registry of Exonerations, points to the nationwide spread of so-called “conviction integrity units” – dedicated teams of experts set up in largely city-based jurisdictions to consider possible miscarriages of justice. There are now 15 such units in the country. Six were created last year alone.

Samuel Gross, a professor at the University of Michigan law school where the registry is based and who wrote its annual account, said that “across the country reforms are slowly spreading. More prosecutors are working hard to identify and investigate claims of innocence.”

But Gross pointed out that the vast majority of jurisdictions, including Los Angeles and most smaller towns and cities, still lag behind, rendering the chances of an innocent prisoner finding relief in most of America much more tenuous.

“If the number of conviction integrity units keeps on increasing they will still only touch on a fraction of the prosecutorial offices in the US,” he said.

The issue of the reliability of criminal convictions has recently been brought to a wide audience by the podcast Serial. It explores the case of Adnan Syed, sentenced to life in Baltimore in 2000 for the murder of his former girlfriend, Hae Min Lee.

The podcast went viral, and was downloaded more than five million times. Though she was hesitant to draw conclusions, its reporter, Sarah Koenig, took the listener deep into the messy, conflicted world of many criminal convictions.

One of the striking features of last year’s unprecedented batch of exonerations was the high proportion among them of defendants who pleaded guilty to crimes they did not commit. Some 47 of the 125 innocent prisoners – almost four in 10 – participated in their own wrongful conviction by agreeing to guilty pleas, mostly in cases involving drug possession.

The high number has baffled and alarmed the registry’s experts. Two possible explanations have been put forward – the first is that people pleaded guilty to possession of drugs, unaware that the chemicals they were carrying were in fact either harmless imitations such as talcum powder or legal pharmaceutical medicines.

Police field drug testing kits are notoriously unreliable, so much so that their results are not accepted as evidence in criminal trials. Many of the exonerations involved cases in which full forensic lab tests of the drug samples found them to contain no illegal chemicals at all.

The second, and more likely explanation, is that defendants were put under so much pressure to cut a plea bargain with prosecutors, with threats of long prison sentences hanging over them if they pleaded not guilty, that they acquiesced to their own wrongful conviction despite their knowing that they were innocent. Gross said that this risk was particularly high for people who already had a criminal conviction.

In Harris County, Texas, which covers Houston, a post-conviction review section set up by the district attorney has made strenuous efforts to uncover erroneous drug testing.

The team there has prioritised full crime lab analysis of drug samples in cases in which defendants pleaded guilty, and found a shocking number came up negative for any illegal substances. That accounted for an extraordinary 33 exonerations in drug cases in Houston.

The impressive efforts by Houston’s prosecutors raises a question: how many other similar cases of people languishing in prison on drugs convictions based on faulty drug tests are there in jurisdictions across the country where prosecutors are not so diligent?

“If a prisoner is wrongfully convicted of a drug charge in Houston there’s today a good chance they will be found and saved,” said Gross. “Anywhere else in the country, there’s not much chance at all.”