According to a probable cause statement released by police Monday, Megan Huntsman said that between 1996 and 2006, she gave birth to at least seven babies at her home and that all but one of them were born alive.
Huntsman, 39, said she killed them immediately after they were born, and put their bodies inside the boxes. The statement said each baby was wrapped in either a towel or a shirt, and placed in a plastic bag.
Huntsman is being held on $6 million bail — $1 million for each baby she's accused of killing. It wasn't immediately clear if she had an attorney.
Huntsman was arrested Sunday on six counts of murder after police found the infants' tiny bodies. A seventh baby found appears to have been stillborn, Utah County Attorney Jeffrey Buhman said.
Formal charges have not yet been filed against Huntsman and no other arrests have been made but Buhman said the investigation remains open.
Investigators were trying to determine if the seven babies had the same father or multiple fathers, Buhman said.
The gruesome case has raised a series of questions about how the killings occurred despite Huntsman carrying out what neighbors said seemed like a normal existence. Police declined to comment on a motive and on what Huntsman said during an interview with investigators.
Her estranged husband found the first infant's body while cleaning out the garage after recently getting out of prison. Authorities do not believe he was aware of the killings and he isn't a person of interest at this time.
Police Capt. Michael Roberts said officers responded to a call from him Saturday about a dead infant, and then they found the six other bodies.
Family and neighbors identified the estranged husband as Darren West, who has been in prison on drug-related charges.
Roberts said police believe West and Huntsman were together when the babies were born.
"We don't believe he had any knowledge of the situation," Roberts told The Associated Press
Asked how West could not have known about the situation, Roberts replied, "That's the million-dollar question. Amazing."
The babies' bodies were sent to the Utah medical examiner's office for tests, including one to determine the cause of death. DNA samples taken from the suspect and her husband will determine definitively whether the two are the parents, as investigators believe.
Huntsman also has three daughters — one teenager and two young adults — who lived at the house.
Neighbors in the middle-class neighborhood of mostly older homes 35 miles south of Salt Lake City say they were shocked by the accusations and perplexed that the woman's older children still living in the home didn't know their mother was pregnant or notice anything suspicious.
Late Sunday, West's family issued a statement saying they were in a "state of shock and confusion."
"We are mourning this tragic loss of life and we are trying to stay strong and help each other through this awful event," the statement said before asking for privacy.
West pleaded guilty in federal court in 2005 to two counts of possessing chemicals intended to be used in manufacturing methamphetamine, court records show. In August 2006, he was sentenced to 9 years in prison, but appealed the term three times. He maintained his innocence and said he never had any intention to manufacture meth.
West's sister Sarah Wright wrote to federal district court in 2006, saying West is a good father to his three daughters. She said he worked at an excavation company for 11 years and is an avid outdoorsman who likes to fish and camp.
"Darren is such an awesome dad," she wrote.
Neighbors told the AP they were shocked and horrified by the accusations of what went on inside the home. None of them even knew Huntsman was pregnant in recent years.
The family members seemed like nice people and good neighbors, said Aaron and Kathie Hawker, who lives next door.
Huntsman moved out several years ago, leaving her three daughters to live alone, the Hawkers said. They weren't sure where Huntsman has since been living.
Years ago, Huntsman baby-sat the Hawker grandchildren and they were friendly with each other.
"It makes us so sad, we want to cry," Kathie Hawker said. "We enjoyed having them as a neighbor. This has just blown us away."
Aaron Hawker said he talked with West on Saturday morning. He told Hawker he was cleaning out the mess in the garage.
"Two hours later, suddenly we had all these policemen here," Aaron Hawker said.
Fred Newman, a neighbor whose cousin is the husband's mother, said he's perplexed how the three oldest daughters living there didn't know about what police say was going on. He said the girls didn't always park their cars in the garage, but did sometimes in the cold winter months.
He said he has used his snow-blower to clean off the driveway of the home and the young women would thank him.
The girls were normal youngsters, coming and going often, neighbor Vickie Nelson said.
"It's shocking and kind of morbid and strange," Nelson said as he looked across the street at the garage from her from lawn.
Roberts said the case has been "emotionally draining" and upsetting to investigators. He was at the home when the bodies were discovered.
"My personal reaction? Just shocked. Couldn't believe it. The other officers felt the same," the 19-year police veteran said.
"They got more and more shocked each box they opened," Roberts said.
Associated Press writer Michelle Price in Salt Lake City, Martin Griffith in Reno, Nev., and Annie Knox in Salt Lake City contributed to this report.
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.