A decade ago, Shelby Herchak was vilified as a "baby killer" in Calgary, identified that way in news reports and on social media.

Then an 18-year-old mother, Herchak was charged with second-degree murder in the death of her 26-day-old son Daniel in 2010 after a medical examiner's report identified several injuries, one at least a week old.

Herchak maintains she accidentally dropped her baby in the middle of a restless night.

Now evidence is emerging of a major disagreement about findings gleaned from the infant's autopsy — a dispute that appears to have raised doubt about the murder charge.

A document obtained by The Fifth Estate as part of an investigation into some autopsies in Alberta a decade ago states that in 2012, the Office of the Chief Medical Examiner changed the "manner" of death in the baby Herchak autopsy report from "homicide" to "undetermined."

The office also looked into the possibility that the baby may have died from a "short fall" and not from a deliberate intent to injure.

Correspondence indicates the information was provided to the prosecution in the Herchak case at the time, but despite that, the second-degree murder charge remained in place.

Herchak told The Fifth Estate she only learned of the change in the manner of death after journalists recently discovered the records buried in a civil court file in Calgary.

"That could have drastically changed everything," said Herchak, who spent time in prison.

"This document should have been open to everybody."

Without knowing about the other pathology evidence, Herchak said she eventually agreed to a plea bargain of manslaughter in October 2013 in order to avoid a possible life sentence on the second-degree murder charge. She said she felt powerless in the face of the testimony of the pathologist who conducted the autopsy.

Dr. Evan Matshes studied at the University of Calgary. He performed autopsies at the Calgary Office of the Chief Medical Examiner in 2010 and 2011. (University of Calgary)

The law requires an accused be provided all relevant records obtained by the prosecution, a process known as disclosure.

The Alberta Crown Prosecution Service declined to answer a series of questions in emails and letters sent by The Fifth Estate over the past several weeks about what happened to the records that mentioned an undetermined manner of death.

Herchak's own lawyer, Kim Ross, has also not responded to several phone calls and emails from The Fifth Estate about whether or not he was provided with that additional medical report that could have been used in her defence.

Medical examiner's findings reviewed

At the centre of the Herchak autopsy dispute was Dr. Evan Matshes, a former medical examiner in Alberta who conducted more than 250 autopsies for the province in 2010 and 2011.

After his departure from that role, questions were raised about some of his findings. That prompted the province to hire a panel of forensic pathologists in November 2012 to review 14 of his cases. They concluded he had made "unreasonable" findings in 13 of them.

Matshes has disputed the conclusions of the external panel and said he is the victim of "local politics and personal vendettas." He stands by his work.

The Fifth Estate reported last month that the external panel of three experts disputed two key aspects of the original Herchak autopsy. The experts disagreed with Matshes's statement that there was a brain injury that was at least a week old.

"We do not agree that this represents a previous injury of seven-15 days duration," they wrote.

Those three forensic pathologists also wrote they were "concerned" that what Matshes described as a second fracture may have actually been a natural separation in an infant's skull.

During the same period, the Office of the Chief Medical Examiner was involved in preparations for Herchak's trial. Documents obtained by The Fifth Estate indicate a debate over the observations Matshes made after conducting Daniel Herchak's autopsy.

On one side was the report by Matshes, who by this time had left Alberta to work in the United States.

On the other side was the new report by the pathologist who had been asked to redo the Matshes autopsy for the Office of the Chief Medical Examiner. Dr. Elizabeth Brooks-Lim was later promoted to Alberta's chief medical examiner, a role she will soon be leaving .

Brooks-Lim did not return several messages asking for comment.

Before she was Alberta's chief medical examiner, Dr. Elizabeth Brooks-Lim took a second look at the autopsy report of Daniel Herchak, a 26-day-old infant who died in 2010. (Office of the Chief Medical Examiner of Alberta)

The documents show that the Crown prosecution service was in communication with the Office of the Chief Medical Examiner when it took a second look at Matshes's autopsy.

"I have been given the onerous task of rewriting the report from scratch," Brooks-Lim wrote a colleague in a July 7, 2012, email. "I also have a tight time limit placed upon me by Crown and have been asked to complete this case in a month... The case is due for trial."

I'm disturbed by all of this. - Kyla Lee

Documents show that once Brooks-Lim questioned the original homicide finding and began looking into the possibility of an accidental death, Matshes wrote a letter directly to the provincial justice minister to complain about the review of his work.

Matshes copied his Sept. 10, 2012, letter to Jonathan Denis to several others, including the trial prosecutor in the Herchak case, the chief medical examiner and the Calgary chief of police.

"I am concerned that the motivation for this review … is to discredit me rather than seek the truth," Matshes wrote.

Matshes told the minister that he recently obtained three opinions from other forensic pathologists who reviewed his work and supported his findings.

Two months after Matshes raised those concerns about the Brooks-Lim review, Alberta's Justice Ministry hired the independent panel of three experts to review some of his work. They would also dispute some of his key findings on the Herchak case.

Report alone could have changed case: lawyer

This evidence, says one legal expert consulted by The Fifth Estate, appears on its own to raise the possibility of a miscarriage of justice.

"I'm disturbed by all of this," Vancouver criminal defence lawyer Kyla Lee told The Fifth Estate. "From my perspective, reasonable doubt was created by these medical reports."

Lee, who specializes in disclosure issues, said the Brooks-Lim report alone could have changed the outcome of this case, and said that all opinions on the Daniel Herchak autopsy should have been presented to court.

Even based on the limited documentation she reviewed, Lee said that had she been Herchak's defence lawyer, she would have tried to get the case dismissed.

"I would have hoped they dropped the charges… I think, based on the second medical report, it could have happened," Lee said.

While The Fifth Estate has reviewed summaries of the Matshes and Brooks-Lim reports, journalists have not obtained the complete documentation, which may provide additional context.

Shelby Herchak has requested her case file from her former lawyer but as of publication had not yet received it.

One of the unanswered questions in the Herchak case is why, despite the additional evidence that might have been used in her defence, all parties signed an agreed statement of facts that made no mention of the Brooks-Lim report or the findings of the expert review panel.

Herchak was sentenced to 5½ years, less time served, in prison in 2014 after taking a plea bargain for manslaughter in the death of her son. (Meghan Grant/CBC)

However, it did include findings that appeared to be in dispute. In particular, the agreement stated as fact that there was a "prior, healing, brain injury" that was "seven-15 days old" and a "fracture at the back of the head." Both those findings were questioned by the expert review panel.

When asked by The Fifth Estate, both the former and current heads of the Alberta Crown Prosecution Service said at least one member of the expert panel reviewed the medical aspects of the agreed statement of facts to confirm their accuracy.

If that is the case, it appears that one of the three medical examiners changed positions and supported evidence they once disputed in their earlier report.

Alberta's Justice Ministry did not name the medical examiner who apparently signed off on the agreed statement of facts.

Officials at the ministry did not respond to The Fifth Estate's question about whether it would release the three medical experts from the non-disclosure agreements they signed in order to clarify.

Sentencing didn't include newer report

In addition to the agreed statement of facts, the exhibits filed in court for Herchak's sentencing included Matshes's original autopsy findings but the exhibit lists appears to make no mention of the other reports.

A judge sentenced Herchak to 5½ years, less time served.

Herchak says it was 'horrible' how the justice system treated her during the court process. (Rachel Ward/CBC)

According to a Calgary Herald story at the time, Justice Kristine Eidsvik referred to evidence of "healing from a brain injury," that was more than a week old.

The judge also referred to an additional injury at the back of the head, which had also been questioned by the three medical experts but whose report was not entered into evidence.

"You deliberately inflicted these injuries to Daniel, they were not accidental," Eidsvik told Herchak in the sentencing, according to the Calgary Sun report.

Herchak and her mother sobbed in court when listening to the judge's words, the media report says.

Herchak's lawyer, Kim Ross, told the Calgary Sun he was satisfied with the results.

"I think it's a good sentence. It sided with a lot of what we had submitted."

Alberta Judge Greg Lepp has weighed in on an autopsy debate via a series of letters to The Fifth Estate. He insists that the Alberta Crown Prosecution Service, when it was under his watch, fulfilled its disclosure obligations regarding the external review panel of some of Matshes's work. (CBC)

In a letter written to The Fifth Estate in January , Gregory Lepp, a provincial judge who once led Alberta's prosecutions office, insisted that the expert review panel report was passed on to Herchak's defence counsel.

"With respect to Ms. Herchak, [the prosecution service] fully met its disclosure obligations," Lepp wrote.

After exchanging a series of letters about the expert review panel documents, Lepp said he would not be responding to any additional questions because of an ongoing external counsel review of the prosecution service .

The Fifth Estate asked Alberta's Justice Ministry to comment on the Brooks-Lim report. Officials there declined to answer questions, also citing the ongoing investigation.

Herchak 'angry and frustrated'

Today there are lingering questions about why the Justice Ministry never held a final review of Matshes's work that it once said the "administration of justice" demanded.

In November 2013, the ministry agreed in court to "quash" the expert review panel results, after Matshes had successfully argued he had not been given time to respond.

Matshes continues to work as an expert witness and forensic pathologist in the U.S. While on contract in Texas, his company came under scrutiny for allegedly using body parts for research without permission . The company's Texas office was raided by the FBI in September 2019. The investigation is ongoing. Matshes denies all allegations and has not been charged.

Herchak said she is disappointed with everyone involved in her case who knew about the evidence that she believes would have cleared her.

"I'm angry and frustrated."

Herchak said she feels the justice system treated her "horrible, honestly, for the whole process."

If you have tips on this story, email Harvey.Cashore@cbc.ca or Rachel.Ward@cbc.ca, or call 416-526-4704 and 403-521-6045.

Follow @harveycashore and @wardrachel on Twitter.

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