Don't speculate that 5-month-old Ryan Stallings died of natural causes, McElroy told the jury. "You might as well speculate that some little man from mars came down and shot him full of some mysterious bacteria."

"Don't try to understand why Patricia Stallings poisoned her child by feeding him from a baby bottle laced with antifreeze, he told them. "The point is she did it, Only she could have done it," he said. "Only she would've done it."

It would be more than 10 hours before jury foreman Delmar Fisher would stand and tell the court that the jury had found Stallings guilty of first degree murder. It would be more than a month before Circuit Judge Gary P. Kramer would sentence her to life in prison without parole, as friends and family members wore T-shirts pleading. "Please help us; Patricia Stallings is innocent."

And it would be more than eight months before McElroy finally would come before a crowd of reporters in downtown St. Louis to tell them that there had been a terrible mistake. Stallings, be said, did not murder her son after all.

He had been wrong, McElroy said. The jury had been wrong. All of the experts, he said, were wrong,

Still a month after murder charges were dropped against Stallings, the man who performed the autopsy on Ryan Stallings has steadfastly refused to change the child's death certificate. Dr. Phillip Burch, St. Louis' deputy chief medical examiner, insists Ryan was poisoned.

But McElroy says he has no question about Patricia Stallings' innocence. "Its difficult at any time to setup up and say a mistake had been made," he said, "but my gosh, there's a time when it just has to be done."

"This," "says St, Louis lawyer Robert F, Ritter, "is an incredible story." "This is not a situation where a crime was committed and the wrong person was accused and convicted," Ritter said. "It's a situation where there never was a crime in the first place."

Ritter is representing the Stallings family in a medical malpractice and wrongful death lawsuit against Cardinal Glennon Children's Hospital, St. Louis University Hospital, SmithKline Beecham Clinical Laboratories and several physicians who played key roles in the Stallings case.

"I don't like to classify people as bad guys or good guys," Ritter said. "This is a situation where mistakes allegedly were made, and they were compounded and reinforced. And, in my opinion, that led to a collapse in our medical system and in our legal system which is unprecedented in my experience."

Prosecutor McElroy, who had been in office just one month when the Stallings case came to trail, says it will be impossible to make up for what happened to Patricia Stallings. "As sad as it is that she had to suffer what she has, I think the final outcome shows a real strength in our system of justice," McElroy said.

The white frame house where Patricia Stallings lives, and where they were living summer during the summer of 1989, is just off South Lake Drive north of downtown Hillsboro. The back of the house overlooks Lake Wauwanoka, a large, private lake surrounded by a variety of both modest and more expensive homes. A large American flag flies from one side of the house; the Stallings name is on the mailbox on the street.

Patricia, David and Ryan had moved into the white house from St. Louis a little over a month before Ryan was first hospitalized, "He had my hair and David's face, Patricia Stallings said of her baby, He had dimples and big blue eyes." "That truly was the happiest time of my life. Everything was perfect, everything. A new house, a new baby. I mean, what could be wrong?"

On the night of July 7, 1989, a Friday, Stallings said she gave Ryan his evening bottle before putting him to bed. The child immediately threw it up.

On Saturday, she said, the baby seemed to be feeling better. Stallings went swimming at her sister's house and left Ryan with her husband.

By Sunday morning, though, she said, Ryan's condition had begun to deteriorate, He was lethargic, could not keep his food down and he was breathing hard, she said. She made arrangements to meet a doctor at the emergency room of Children's Hospital.

But Stallings said she got lost, and instead of going to Children's Hospital she drove to Cardinal Glennon Hospital.

On July 12, after a series of test that purportedly showed high levels of ethylene glycol in Ryan's blood, pediatrician Dr. Robert Lynch signed an affidavit saying he believed the child might have been poisoned. The case was referred to the Missouri Division of Family Services. which placed Ryan in protective custody almost immediately. Ryan was discharged on July 17 and placed in a foster home.

"It happened real fast," Patricia Stallings said, "I kept thinking this would get straightened out, I thought somebody would figure this out, they'd say "oops," and we'd all go home."

On Sept. 4, four days after a brief visit with his mother. Ryan was hospitalized a second time. The next day, Stallings, who authorities said had poisoned her son during the visit was arrested at her home, handcuffed and taken away in a police car as her husband followed behind. She would spend the next seven months in jail.

It was shortly after her arrest that Stallings learned that her son had died. "I don't thing I believed it," she said, "I just went around that entire day, saying, "no, no, no...l had just seen him; I had just spent the night with him, I was mad at everybody. The whole thing was just so absurd."

Although she didn't know it at the time of her arrest, Stallings was pregnant with the couple's second child. It would be that child who ultimately would be the key to finally freeing Stallings.

Even before McEIroy took over the Jefferson County prosecutor's office in January 1990, he said, he began to immerse himself in the Stallings case. Once he took office, he said, he interviewed all of the witnesses himself; he talked to all of the experts and reviewed all of their findings.

He said he particularly was troubled by press reports and suggestions from Stalling's attorney at that time, Eric Rathbone, that Ryan might have died of an extremely rare genetic disorder called Methylmalonic acidemia, or MMA.

It had been the birth of the Stallingses' second son, David Jr., that focused attention on the possibility that MMA may have played a part in Ryan's death. MMA, which affects one out of every 48,000 children, causes a buildup of dangerous acids within a child's body. When Children's Hospital diagnosed David Jr. with the disease, experts said there was a one in four chance that Ryan too had suffered from the rare genetic disorder.

"I had heard enough to be concerned" McElroy said.

Two major pieces of medical evidence, though, seemed unshakeable, McElroy said, and convinced him that Ryan had been murdered.

The first was the finding of ethylene glycol in infant's body by both the SmithKIine laboratory and a toxicology laboratory at St Louis University. Even if Ryan suffered from MMA, the disease would not account for the levels of ethylene glycol (the active ingredient in antifreeze) found in the baby's blood. Rathbone, McElroy said he had more than nine months to find an expert to explain the finding of ethylene glycol in the boy's body and had been unable to do it. A bottle of antifreeze had been found in the Stallingses' basement.

The second overwhelming piece of medical evidence, he said, was the autopsy's finding of a material that appeared to be calcium oxylate crystals in the child's brain and other body organs. Medical experts had told McElroy that the crystals were consistent with ethylene glycol poisoning.

It seemed from the beginning that the key to Stallings' defense was to somehow show that Ryan's death might have been caused by MMA and that he was not poisoned at all, much less by his mother.

Rathbone, who said he had agreed to take Stallings' case as a favor to the family and because "it seemed nobody else would take it," said he hoped to prove that the infant had died of an in-born metabolic disorder. "The problem is that there was no one who would back me up on it" Rathbone said.

Rathbone said he did extensive reading on the subject and even spoke to a nationally known expert on metabolic diseases. That expert, Rathbone said, told him there was no way that any metabolic byproducts of MMA could be mistaken for ethylene glycol in lab tests.

Rathbone, who Said he has a degree in biochemistry, Said he also looked at the test results of SmithKline and St. Louis University and determined that there was no reason for him to question their findings. "I went back to my old textbooks to make sure," Rathbone said.

By the opening day of the trial, Rathbone had subpoenaed no expert witnesses to testify for Stallings. He said he believed that none was available.

Rathbone also did not take depositions of any of the state expert medical witnesses; he said after the trial that he had no reason not to trust their findings.

Still, Rathbone said he had hoped to introduce evidence at the trial that Ryan's brother, David Jr., suffered from MMA and, as a result, there was a one in four chance that Ryan too had suffered from the disease. But the evidence, which seemed key to Stallings' defense, never got to the jury.

At one point, early in the trial. Judge Kramer told Rathbone: "You have to prepare and subpoena the evidence necessary to prove your theory to the case. That's not my responsibility."

Six months after the trial, Prosecutor McElroy acknowledged in a motion filed with the court that Rathbone's defense had been ineffective; Kramer agreed to grant a new trial.

"That is very unusual." Kramer said of McElroy's acknowledgment of ineffective counsel. "It's the only time I've every known it to happen."

Rathbone said he is convinced he did the best job he could under the circumstances.

The first soft spots in Jefferson County’s case against Stallings began to show as early as April 1990, a full nine months before her trial.

News accounts that month were reporting that David Jr., born on Feb. 17, had tested positive for MMA. Dr. Christopher Long, head of St. Louis University's toxicology laboratory and one of those who previously had found ethylene glycol in Ryan's blood, agreed to turn over a tiny bit of the fluid to Dr. James Shoemaker, who had just set up a genetic disorder testing laboratory at the University.

Shoemaker said he received about one-tenth of a teaspoon of Ryan's blood.

Using a test designed to detect MMA in urine, Shoemaker discovered on April 21, 1990, that Ryan Stallings, in all likelihood, suffered from MMA.

While he also found what he believed to be a trace of ethylene glycol in the blood, Shoemaker said it would not have been in high enough concentrations to have killed the boy.

Shoemaker reported his findings to Long, and a meeting was held among some of the university's senior staff. Most agreed that Ryan likely had MMA, but that it was not the disease that had killed him. They believed that much of the ethylene glycol that had been noted in the child's blood in earlier tests had dissipated during storage. They still felt Ryan had been poisoned.

The next January, shortly before the trial, Shoemaker said, he received a phone call from the Jefferson County prosecuting attorney's office. It was the first time he had reported his findings to them.

"I thought, 'Here’s a very rare case where a child with a genetic disease also could have been poisoned,' and I said as much to the prosecutor's office," Shoemaker said.

McElroy said Shoemakers findings were relayed to Rathbone. But Rathbone contends that had he known that Shoemaker found only a trace amount of ethylene glycol in Ryan's blood, he would have pursued it. Rathbone said he never contacted Shoemaker; he said he didn't need another witness saying that Ryan probably was poisoned.

Despite all of the local newspaper and television reports of the Stallings case, it was a May 8 national showing of the television program "Unsolved Mysteries" that marked the beginning of the end of Patricia Stallings' long ordeal.

Dr. William S. Sly, professor and chairman of the department of biochemistry and molecular biology at St. Louis University, was watching the program and realized that no other tests were being performed on Ryan Stallings' blood.

In late June, after additional tests by Shoemaker, Sly wrote a letter to a university official. The letter was relayed to McElroy.

In the letter, Sly said Shoemaker reached three conclusions:

* He confirmed the absence of ethylene glycol at the time the tests were done in samples taken from Ryan before his death.
* He confirmed abnormal elevations of organic acids in Ryan's serum "that make the diagnosis of MMA virtually certain.
* He found that one of the compounds that had been elevated by Ryan's disease could be confused with ethylene glycol, "at least by older gas chromatographic techniques."

Shoemaker and Sly have said that they believe any traces of ethylene glycol found in some of Shoemaker's tests were simply contamination that might have been caused in the process of sterilizing equipment used to draw blood for the tests.

Similar traces of ethylene glycol were found in tests run on patients who had not been poisoned, they said.

McElroy said that while he was intrigued by Shoemaker's findings, he still wasn't sold that Patricia Stallings might be innocent.

It wasn't until McElroy met with Dr. Piero Rinaldo, a young, world-renowned genetics expert from Yale University, that he realized that Ryan likely had died of MMA and not anti-freeze poisoning.

That meeting, involving McElroy, Rinaldo, Ritter and registered nurse Judy Stinson, who works in Ritter's law firm, took place in Ritter's downtown St. Louis law offices.

"I met with {Rinaldo], questioned him for an entire day," said McElroy. "We went back over all the raw data. The bottom line is that the experts' conclusions were not supported by the data."

Earlier this month, in a telephone interview from his Yale office, Rinaldo was highly critical of the test results generated by SmithKline and St. Louis University that had found high concentrations of ethylene glycol in Ryan's blood.

The quality of the tests, Rinaldo said, was "totally unacceptable." They were, he said, "unbelievable; out of this world."

"I was astonished," Rinaldo said, "I couldn't believe that somebody would let this go through a criminal trial unchallenged,"

In independent tests, Rinaldo said, he found no evidence of ethylene glycol in Ryan's blood. He also said he could find no evidence in test results done on the baby bottle that any ethylene glycol had been found there. Even further, Rinaldo said Cardinal Glennon's treatment of Ryan - treatment that included fasting and use of ethanol to limit the effects of ethylene glycol poisoning - were inappropriate for a child with MMA,

In their wrongful death suit, the Stallingses maintain that the misdiagnosis resulted in improper treatment that led to Ryan's death.

Despite Rinaldo's conclusion that Ryan was not poisoned, McElroy had one lingering question. How, he asked, could Rinaldo explain the crystals found in Ryan's autopsy - crystals similar to the type found in ethylene glycol poisoning?

Rinaldo said there was a high likelihood the crystallization had come as a direct result of the ethanol drip used in the hospital to treat Ryan's suspected ethylene glycol poisoning.

"Dr. Rinaldo was very persuasive," McElroy said. "I was persuaded that she didn't do it. In my mind, Ryan was not poisoned. My charge, as a prosecutor, is to seek justice, and I think justice required a dismissal."

A month after the charges were dropped against Patricia Stallings, there has been no move to change the cause of death on Ryan's death certificate. The certificate continues to read homicide by ethylene glycol poisoning.

Burch, the deputy chief medical examiners who performed the autopsy and testified at Stallings' trial, said, "I signed the autopsy report; I have seen nothing to change my opinion."

Burch said he had worked with Dr. Long many times, and "I have never known him to make a mistake. "There is no reason for him to say that ethylene glycol is present when it's not. He does not find something when it's not there."

Burch said he also vehemently disagrees with Rinaldo's claim that the tests on Ryan's blood samples were flawed. "Until I see a toxicology report, I will not seriously consider his report."

"As far as I'm concerned, the child was poisoned to death," Burch said. "The tests were modern, up-to-date tests. The diagnosis was fairly definitive."

In a prepared statement, administrators at Cardinal Glennon said that "blood drawn at Cardinal Glennon for use in diagnosing the child's illness was analyzed by two outside, highly reputable laboratories.

"The care provided to the patient by Cardinal Glennon was based on those test results."

St. Louis University. which performed laboratory tests in the Stallings case, has declined to comment on the case.

Tobey Dichter, a spokeswoman for SmithKline. said, the laboratory has a policy of not commenting on pending litigation "in fairness to all parties."

Meanwhile, Patricia and David Stallings say they are still trying to cope with the death of one son and with the disease that threatens the life of another son. They have been told his disease will be difficult to manage. It will be a long, hard struggle, they say.

The family recently brought David Jr. home from Children's Hospital; his room is the nursery that had been decorated for Ryan.

"We've gone through so much, there's really no use in being angry," David Stallings said. "It doesn't do anything but cause trouble.

"I want the public to know what really happened. It’s like a mission for me, to assure that other families don't have to go through what we went through "

"We have a lot of things we need to do," said Patricia Stallings. "A lot of things we need to catch up on."