The years-long media frenzy over the trial of Casey Anthony is reaching its denouement. On Tuesday, the 25-year old Florida woman, arrested in 2008 and charged with killing her two-year-old daughter, was acquitted of murder charges and found guilty of lying to police. This morning she received her sentence and headed back to jail. Ever since the verdict was read, cable news has been saturated with overheated speculation as to whether the system of justice had failed by letting Casey Anthony, who was facing the death penalty, live.

It is an important discussion to have, given that it deals with the authority our courts and juries have to impose the ultimate punishment of death. But it is being led by journalists who expected Anthony to be convicted and executed. Fox News' Geraldo Rivera marveled just after Anthony was acquitted that she was “a woman that we felt, just hours ago, just an hour ago, could have been walking down the green mile, down the last walk to the death chamber ... that she would be there, sitting some years from now with needles in her veins, forfeiting her life for that poor child.”

It's impossible to say with complete certainty whether the justice system failed with respect to Casey Anthony. What is known, however, is that the same justice system has absolutely failed catastrophically by sending people to death row for crimes they did not commit. We know this because several of those people have, by dint of good fortune and hard work by lawyers and journalists, been exonerated and set free. But those failures get just a fraction of the media attention paid to trials like that of Casey Anthony.

MSNBC's Chris Hayes illustrated this point on July 5, contrasting the coverage of the Anthony trial to the saga of Cory Maye, who was convicted of the murder of a police officer and sentenced to die after an error-riddled farce of a trial, and freed earlier this week when he pleaded guilty to a less severe manslaughter charge and received credit for time served. As Hayes put it: “The truly horrifying thought, on a day when the country's attention is so focused on murder and justice, is that while a case like Casey Anthony's can command our national attention, there are almost certainly other Cory Mayes out there who languish out of the spotlight.”

Hayes is right. Since 2008, when Casey Anthony became a constant fixture on cable news, The Innocence Project has helped exonerate dozens of wrongly convicted people, including two men sentenced to die for murders they did not commit.

On February 15, 2008, Kennedy Brewer of Mississippi was exonerated of his 1995 conviction for the murder of a three-year-old girl. DNA testing conducted in 2001 proved Brewer's innocence, though he remained in jail for another six years until being released in August 2007. The key evidence against Brewer had been alleged bite marks on the body of the victim that a discredited forensic odonotologist testified could only have come from Brewer. The defense expert argued that they were insect bites. The DNA tests that eventually cleared Brewer also implicated another man, who subsequently confessed to the murder.

On August 25, 2008, Michael Blair of Texas was exonerated of his 1994 conviction for the murder of a seven-year-old girl. Again, DNA testing excluded Blair as the murderer and implicated another man, who had since passed away. Blair had his conviction thrown out and the murder charge dropped. He is still serving a life sentence for other crimes to which he has confessed.

The execution of a prisoner is the ultimate assertion of the state's authority to dispense justice. As such, a wrongful sentence of death is the most egregious error our judicial system can make. These three cases show that these errors are made often -- often enough, you would think, that the media would sacrifice some of the overhyped “trial of the century” coverage to give them the attention they deserve.