Pleasant Grove, Utah: The discovery of seven dead babies in cardboard boxes in a Utah garage has police desperately seeking answers from the mother and other family members about how such a tragedy unfolded over a decade with no one noticing.

Megan Huntsman, 39, is accused of killing her babies after giving birth to the children between 1996 and 2006, investigators said. She was booked on Sunday into the Utah County Jail with six counts of murder. It wasn’t immediately clear if Huntsman has an attorney or why there were six counts and not seven.

The gruesome case has raised a series of questions about how the killings occurred despite Huntsman carrying out what neighbours seemed like a normal existence. Police declined to comment on a motive and what Huntsman said during an interview with investigators.

Her estranged husband made the discovery while cleaning out the garage after recently getting out of prison, and 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 on Saturday about a dead infant, and then they found the six other bodies.

Family and neighbours 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 the man 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.

Neighbours in the middle-class neighbourhood 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.

Police say West made the grisly discovery at the house owned by his parents in a city of about 35,000 people at the foot of snow-capped mountains. It’s a nondescript, newer home with a brick facade and a star ornament hanging by the door.

Several police cars blocked the entrance to the house on Sunday evening as officers milled about with the belongings from the garage strewn across the front lawn.

Late on 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 nine years in prison, but appealed the term three times. He maintained his innocence and said he never had any intention to manufacture meth. It’s unclear when he was released.

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.

Neighbours 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 neighbours, said Aaron and Kathie Hawker, who live next door.

Huntsman moved out several years ago, leaving her three daughters, one teenager and two young adults, 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 neighbour. 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 neighbour 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.

“What’s shocking is the three older ones living there and not noticing that their mother was pregnant,” Newman said.

He said he has used his snowblower to clean off the driveway of the home and the young women would thank him.

The girls were normal youngsters, coming and going often, neighbour 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.