In the classic 1956 Alfred Hitchcock film, "The Wrong Man," Henry Fonda plays a man whose life is shattered when he is wrongfully accused of a robbery and is nearly convicted based on eyewitness testimony. The film, based on a true story, is built on a fact that attorneys and judges have long known - while eyewitness testimony can be compelling and convincing, it is notoriously unreliable.

Last week, New Jersey's Supreme Court issued guidelines that recognize this and attempt to mitigate problems that can be caused by faulty testimony.

The testimony of witnesses remains an important tool for prosecutors. What could have a more powerful impact on a jury than seeing a victim point to a defendant in court?

It wasn't until it became possible to use DNA to re-examine convictions that the full extent of the weakness of eyewitness testimony became apparent.

In case after case, the evidence has shown that juries give too much credence to faulty human memory. Some of those cases are notoriously dramatic.

In 2011, a Texas man was freed after 30 years in prison when DNA evidence showed the single eyewitness testimony that convicted him of rape and robbery was wrong. A Florida man convicted of rape by eyewitness testimony was freed by DNA evidence after spending 20 years in prison.

In fact, more than 75 percent of convictions that have been overturned by DNA evidence were based on eyewitness testimony.

DNA doesn't lie. It doesn't forget, and it can't be influenced by the behavior of investigators. None of that can be said about eyewitnesses.

Studies show that the accuracy of identifications can be influenced by whether or not the victim and suspect are of the same race, by whether a weapon was involved in the crime, by the amount of time a victim saw a perpetrator and by the amount of time that passed between a crime and an identification.

Witnesses can also be misled, unintentionally or on purpose, by how lineups and photo identifications are handled by police.

When looking at photographs, witnesses select the wrong suspect about a quarter of the time. And even when the suspect is left out of a lineup, witnesses will still pick out someone more than a third of the time.

Fortunately, New Jersey's Supreme Court is ahead of the rest of the nation in recognizing this and doing something about it.

Beginning in September, judges will be required to instruct juries about the potential unreliability of eyewitness testimony.

The court also instructed police to record or transcribe their conversations with witnesses about identifications, and gave judges the discretion to disallow testimony if the new standards aren't followed.

The guidelines add important safeguards to the state's criminal justice system.