Police in Michigan arrested the 27-year-old Natzel and are holding him in lieu of $500,000 bond at the Lenawee County Jail in Adrian, a small city near the Ohio border.
A few days after the indictment, Phoenix homicide detective Jack Ballentine flew to Michigan to see if Natzel would speak with him. However, Natzel told Ballentine that his attorney in Arizona previously advised him not to discuss the case.
Ballentine also interviewed acquaintances of Natzel's in the town of Owasso (about half an hour from East Lansing, the home of Michigan State University), where Natzel had been living since shortly after his daughter died.
New Times detailed the tragic story of Abigail Rose Minor's death in its "Murder City" series ("The Case of the Two Abigails," May 18, 2006). A separate case where a child named Abby had died under suspicious circumstances was also profiled in the story, but that death turned out to be a terrible accident.
Early on the evening of August 27, 2005, Natzel told his wife, Amy Minor, in a phone call that he had found his daughter inside a cardboard toy box with a domed lid.
According to Amy's later account, Natzel had claimed before hanging up the phone that the baby was "choking."
But phone records later indicated that Natzel did not call 911 for assistance until more than 30 minutes after that. When paramedics got to the couple's apartment in north Phoenix, Abbey Minor was dead.
Natzel was unemployed at the time, and was staying at home with Abbey while his pregnant wife worked full-time at a Phoenix pharmacy. Natzel told police that he had been spending his days tending to Abbey inside their apartment as he played hour upon hour of video games.
Natzel insisted that he never physically abused Abbey, whom he told police was named after the Beatles' famous record Abbey Road.
But an examination of the baby's body at John C. Lincoln-Deer Valley Hospital shortly after she died revealed fresh abrasions on her forehead, small bruises above both eyes and a bundle of inexplicable bruises. The back of the baby's head also was badly swollen.
Detective Ballentine interviewed Eric Natzel and Amy Minor at the hospital separately on that night last August.
Amy defended her husband in that first, brief interview, but later turned against him and alleged that he had been physically abusing her for some time.
Ballentine asked Natzel that night to explain the many bruises on the baby's body.
"They weren't there this morning," Natzel told the detective, noting that he'd showered with his little daughter sometime before noon. "I don't even remember seeing them when I picked her up [out of the toy box]."
Natzel also conceded that Abbey had been in his sole care and custody from the time his wife had left for work in the early afternoon (a few hours after the shower) until he had allegedly "discovered" her in the toy box.
Natzel offered to take a polygraph test, but canceled an appointment a few days later.
His explanations were less than satisfactory to Ballentine. Sorting out what happened to Abbey has become as important to the detective as unraveling any of the more high-profile cases he has investigated during his career.
It clearly galled the detective and the other cops present at the hospital after Abbey's dreadful death that Natzel seemed almost casual about her demise.
The cops observed that, instead of showing signs of grief (which may range from hysteria to catatonia), Natzel laughed and joked with friends who had come by after they heard the grim news.
Natzel left the hospital that night with his parents. His wife Amy left with her parents. At the time, she was just a few weeks away from giving birth to her second child.
The couple have not seen each other since that night. Amy Minor and her healthy baby boy, Ian, are living with her mother in Glendale.
As his investigation moved forward, Ballentine became convinced that Natzel had stuck Abbey in the toy box after she had interrupted his video-game playing, and then repeatedly pounded the baby in the back.
Last February, a county medical examiner concluded that Abbey had suffocated inside the toy box but listed the manner of her death as "undetermined," not as a homicide or an accident.
Dr. John Hu wrote that he could find no evidence of internal injuries, bone fractures, or any sign of what's known as "shaken-baby syndrome."
The pathologist also noted that the bruises, however plentiful, did not kill the little girl.
Importantly, though, Dr. Hu concluded that many of the multiple injuries the child suffered particularly the ugly and fresh cluster of bruises in the middle of her back had been "intentionally afflicted" by another person.
That comported with Ballentine's theory that Eric Natzel had smashed Abbey with his fists, probably after crunching her into the domed toy box.
Many more months of continued investigation ensued, including consultation with medical experts in Arizona and elsewhere, before county prosecutors decided that they had enough evidence to convict Natzel of child abuse.
For myriad reasons, child abuse cases akin to this can be difficult to prove beyond a reasonable doubt. Prosecutors often must rely on expert witnesses to try to convince jurors that the accused committed the crime.
In this case, defense attorneys surely will contend that Abbey's death was a terrible accident, and that if anyone physically abused the baby, it was her mother, not Eric Natzel.
The defense also certainly will ask a judge to suppress Natzel's self-incriminating statements at the hospital on the night that Abbey died.
Natzel faces more than 20 years in prison if convicted on the more serious of the two felony counts, which is classified as a dangerous crime against a child.
Natzel has waived extradition, but it is uncertain when he will be returned to Arizona to answer the charges.