After protests, appeals and public outcry, Troy Anthony Davis was executed Wednesday night by lethal injection. How did this happen with so much doubt over whether he killed the off-duty police officer that night in 1989?

It seems to some that Davis’s life was ensnared in the crosshairs of the justice system’s procedural process, a trap that his defense was unable to pry him from despite 20 years of strategizing.

"The U.S. justice system was shaken to its core as Georgia executed a person who may well be innocent," said Larry Cox of Amnesty International. "Killing a man under this enormous cloud of doubt is horrific and amounts to a catastrophic failure of the justice system. While many courts examined this case, the march to the death chamber only slowed, but never stopped. Justice may be blind; but in this case, the justice system was blind to the facts."

Davis went through a maze of legal procedures since he was charged with the murder of Mark MacPhail, but it seems that it was a mixture of strategic mishaps and procedural pitfalls that landed Davis on death row.

At trial, the prosecution bears the burden of proof to show that a suspect has committed a crime beyond a reasonable doubt. Davis was convicted in 1991 strictly on information provided by eyewitness testimony, without any physical evidence tying him to the crime. While unfortunate, the starkest doubt wasn’t cast upon Davis’s case until witnesses began coming forward and recanting their testimony — some saying they were coerced into making the accusatory statements.

However, Davis was given a second chance at formally casting doubt on his conviction in 2010 when the U.S. Supreme Court reviewed Davis’s case and sent it back to lower court with instructions that an evidentiary hearing be held to allow Davis’s team to present new evidence. But contrasting stories about what happened at the hearing say that between Davis’s defense and a system that forced him to prove his innocence, Davis didn’t have a chance.

"Ultimately, while Mr. Davis's new evidence casts some additional, minimal doubt on his conviction, it is largely smoke and mirrors," he ruled. "The vast majority of the evidence at trial remains intact, and the new evidence is largely not credible or lacking in probative value,” U.S. District Judge William T. Moore said at the conclusion of the 2010 hearing according to the Associated Press.

However, advocates say that the bar was set too high and Davis was essentially forced to prove his innocence, not prove doubt. Moye said that despite having their testimony accepted at trial when presented by the prosecution, witnesses who recanted their trial testimony were not believed by the judge at the hearing.

“What we have in the legal system is an appeals process that is focused on analyzing whether there were errors in the way the trial was conducted, it has nothing to do with reviewing the validity of the conviction, the strength of the case against Troy Davis,” Moye said.

On Wednesday night, moments before Davis’s scheduled execution,the U.S. Supreme Court stepped in again delaying the execution only to issue a one-sentence opinion, affirming the decision of the Georgia Board of Paroles and Pardons.

Davis was executed at 11:08 p.m. EST via lethal injection. Moments before he died, he said: "I am innocent. All I can ask ... is that you look deeper into this case so that you really can finally see the truth. I ask my family and friends to continue to fight this fight."

Prosecutors and MacPhail's family said justice had finally been served. However, with so much doubt surrounding his trial, one has to wonder if that is the case.

(Photo: Tami Chappell / Reuters)