BIRMINGHAM, Alabama - A mother who accidentally left her 11-month-old daughter to die in a sweltering SUV almost one year ago will not face criminal charges.

Jefferson County District Attorney Brandon Falls said he carefully considered the death of Gabriella Gi-Ny Luong, and potential prosecution against her mother, Katie, in their entirety. In the end, Falls said, justice would not be served in possibly sending the grieving mother to prison.

"I have a duty to stand up for Gabriella, and every child, and every adult who is a victim in my jurisdiction. I know that,'' Falls said. "There are those who will disagree with my decision because a child has died, and they want a sense of fairness that comes from a criminal prosecution. But my greatest duty is to do justice. The law allows me to use my prosecutorial discretion to seek that justice. In this case, based on the law and the evidence, I am deciding not to prosecute."

Gabriella, known to family members as Ella, was discovered by her mother about 1:20 p.m. July 17, 2013 still strapped in her car seat in the locked Lexus parked outside the family's Genesis Nail Spa in Homewood. The temperature outside was about 90 degrees; inside the car it was above 125 degrees.

Gabriella was unresponsive. Efforts, first by a nearby business owner and then paramedics, to revive her were unsuccessful. They rushed her to Children's of Alabama hospital anyway, where the staff pronounced her dead a short time later.

The day following Gabriella's death, Katie Luong spoke with AL.com. "I want to tell everybody that I wish I was in that car seat, not her," the weeping 31-year-old mother said. "If I had to die for her to live, I would have done that."

A similar case happened in Calhoun County the month after Gabriella died. Sgt. First Class Katherine Papke, 35, was charged with manslaughter and leaving a child unattended following the August death of her son, Bennett Owen Smith. The second charge was later dropped. A Calhoun County grand jury indicted Papke on the manslaughter charge.

Falls said in determining whether Luong should be charged with a crime for her actions that led to Gabriella's death, he tried to focus on the entire event. "By entire event, I mean everything from the actions that she took prior to the death of Gabriella, through the investigation, and what evidence exists to prove that Katie is guilty of a crime beyond a reasonable doubt,'' he said.

First of all, Falls said, the evidence would show Luong and her husband, Khan, had been trying for some time to have a child. Married for almost 10 years, the young couple tried for years to conceive. Success came only after their church family -- the Vietnamese congregation at North Shelby Baptist Church -- joined in collective prayer for conception for the couple.

"I asked God for this baby,'' Luong told AL.com. "She was our gift from God."

On July 17, 2013, Gabriella was five days shy of her first birthday. Luong left their home that morning with her daughter in the car with the intention of taking the girl to the babysitter. Falls said whether Luong or her husband would take Ella to the babysitter really depended on what they had scheduled for the day, so it would not be considered routine that either one or the other took her.

On that day, Luong began talking on her cell phone during the drive and forgot to stop at the babysitter's house. She continued talking on the phone while driving to work. Once at work, she picked up Gabriella's diaper bag and walked into her business while still talking on the phone.

While at work, Luong made several phone calls. At approximately 1:18 p.m., the babysitter called to ask if she was bringing Ella to her house. At that point, Luong realized that she had not taken the child to the babysitter's house, and that she was still in the car.

"The temperature inside the car that day reached approximately 128 degrees,'' the district attorney said. "Gabriella died of hyperthermia."

Both parents went to Homewood Police Department for questioning. "Both parents were distraught and Katie expressed great remorse at what she had done,'' Falls said. "Katie stated that she believed that she had taken the child to the babysitter and that the child was no longer in the car."

This type of case, he said, falls under the offense of homicide in Alabama. To prove that a person committed a crime, prosecutors have to prove criminal conduct, which means that the person committed an act or an omission that constitutes an offense, and that the person had the mental state required by that offense. Although Falls said his office sees many homicide cases each year, almost all of them involve a voluntary act - which under Alabama law is an act performed consciously as a result of effort or determination. Rarely, he said, do they see cases of criminal conduct by omission, which the law says is failure to perform an act as to which a duty of performance is imposed by law.

"In this case, Katie obviously has a legal duty to protect her child. There is no evidence in the case that this was intentional act, which is to say that there is not evidence that it was her purpose to cause the death of Gabriella,'' Falls said. "So, this would not fall under a voluntary act. Instead, it would fall under an omission- that she failed to protect her child."

Since this was not an intentional act, he ruled out the charge of murder, which requires that she acted intentionally. Then he looked at the charge of manslaughter, that she recklessly caused the death.

To prove manslaughter, the evidence has to show that she was aware of and consciously disregarded the risk that her daughter would die. "Common sense indicates that she, and any parent for that matter, was aware of the risk that leaving her in the car could cause her death,'' Falls said. "However, the evidence does not show that she consciously disregarded that risk. That would be the case if she purposely left the child in the car knowing the risk, but ignored the risk. To the contrary, the evidence is that she was not conscious of the fact that Gabriella was in the car at all."

Falls said next prosecutors look at the offense of criminally negligent homicide. To prove that, he said, there must be evidence that Luong failed to perceive the risk that Gabriella could die in the car, and that the risk is of such a nature and degree that the failure to perceive it is a gross deviation from what a reasonable person would do in that situation. "It is obvious that leaving a child in a car for three hours during July in Alabama is a gross deviation from what a reasonable person would do in that situation,'' Falls said. "The shear minuteness of the number of times that this happens is evidence of how gross a deviation it is."

So the focus then turned to whether Luong failed to perceive the risk. "It is easily arguable that Katie did fail to perceive the risk. She failed to take her child out of the car for three hours, and no reasonable person would do that,'' Falls said. "However, there is also an argument that instead of 'failing to perceive the risk,' that she was completely oblivious of the risk."

In other words, he said, she knew that risk. There is no evidence that she routinely left her child in the car, which would support the argument that she failed to perceive the risk. If asked before Gabriella's death whether she understood that there is a risk of causing death to a child if that child is left in a car, Falls said, Luong would have said that she knows and understands that risk. "It is common sense; everyone knows that risk,'' he said.

That argument, he said, is based on the belief that Luong didn't "fail to perceive the risk," but that she failed to perceive the facts of the situation in which she was in. "She thought that she had taken the child to the babysitter, and she thought that the child was not in the car when she arrived at her business and walked in,'' Falls said. "Therefore, if there is no 'failure to perceive the risk,' then there can be no criminal mental state to prove the crime of criminally negligent homicide."

It is a persuasive argument, he said, but there is little legal precedent because the situation happens so rarely. "I believe that both sides of the argument for criminally negligent homicide could be presented to a jury for them to decide, and rational persons could fall on either side of this argument,'' he said.

Falls said he next looked at other possible arguments that would be made to a jury. One was the concept of mistake. Mistake is not an actual defense to criminal conduct, but it can negate the criminal state that is necessary to prove someone is guilty of committing a crime, he said.

According to Alabama law, "a person is not relieved of criminal liability for conduct because he engages in that conduct under a mistaken belief of fact unless his factual mistake negatives the culpable mental state required for commission of an offense." That, he said, goes along with the argument that Luong failed to perceive the facts of the situation.

"She was under the mistaken belief that her child was not in the car, and that could be argued to be a mistake of fact. That mistake of fact, the argument would follow, would mean that she did not 'fail to perceive' the risk because under her mistaken belief, there was no risk to perceive,'' Falls said. "Thus, she did not have a criminally negligent mental state and could not be guilty of criminally negligent homicide."

Falls said if charges were filed, that argument would likely be made by a defense attorney, and one that would go further toward an acquittal in a jury trial or, possibly, a judge granting of a motion for judgment of acquittal. "As a prosecutor, I have a pretty good idea which way most of my cases will go, but I can never be certain,'' he said. "That is the nature of a criminal trial in front of a jury. In this case, based on this argument, I can just as easily see a trial ending in acquittal as I can a conviction."

So, Falls then looked at the possibility of a criminally negligent homicide charge, and whether there was enough evidence to prove guilt beyond a reasonable doubt. "There is no doubt that Katie Luong is responsible for the death of her child, but that is different than presenting enough evidence to prove that she is criminally liable for that death beyond a reasonable doubt,'' he said.

Falls went through all the probabilities of a trial, the possibility of a conviction and the consequences that would follow.

"If Katie were found guilty, what punishment could I ask for that would possibly rise to the level of punishment she has already received?'' he said. " Even if I were to ask for prison time, I sincerely doubt that there is any judge that would send her to prison. What would a conviction do to her, to her husband, and to her family?"

Through it all, though, Falls wondered one thing: If he prosecuted her, would he really be doing the right thing for the community?

"My duty is to ensure the public safety," he said. "Would I make the community any safer by charging Katie with a crime?"

The answer, he found, was no.

"My duty is to prevent crimes through the deterrent influence of the sentences. Would I deter any crimes through the prosecution and sentence of Katie Luong?" he said.

There is, Falls said, a good argument that the act itself, and the public shock and dismay that followed from the media attention, are a better deterrent than a conviction. "My duty is to the rehabilitation of criminals through the criminal justice system. Is there anything that the criminal justice system has to offer to rehabilitate Katie Luong?" he said. "There is probably no greater rehabilitating influence than the memory of a dead child."