Brittany Pilkington of Ohio has admitted to murdering her three small sons within a 13 month timespan, but why did she do it?

As previously reported by WebProNews, emergency responders tried to save her three-month-old baby Noah on Tuesday, a few days after a court returned the child to her.

In April, four-year-old Gavin died and three-month-old Niall died last summer.

It was when paramedics questioned the coincidence that Brittany Pilkington made her confession.

“She has confessed to placing a blanket over the faces of three of her children and holding them either face down or face up until they expired,” prosecutor William Goslee told reporters on Wednesday.

“Everybody that is involved in this is truly emotionally distraught – including myself, quite honestly – and it isn’t because the system failed,” Goslee said. “It’s because this child is dead. This was not a foreseeable event.”

Mom accused of killing sons, says husband paid more attention to them than to her & daughter: http://t.co/LHnGasaQIo pic.twitter.com/kxnCCgqHj6

— HLN (@HLNTV) August 20, 2015

Needless to say, it is still early in the investigation, but one emerging theory is that the 23-year-old mother feared her husband loved her sons more than he loved her and her daughter.

Estranged from most of her family, Brittany Pilkington reportedly told authorities her best friend was her three-and-a-half-year-old daughter.

“No one could predict the behavior of this mother, a 23-year-old mother who is apparently killing her children in order to preserve the smaller family with her and her daughter and the father of the children,” Goslee said.

Bond was set at $1M for Brittany Pilkington, the mom charged with murder in death of 3 sons http://t.co/Nfd9EKXPH4 pic.twitter.com/cGzAecMsc5

— WHIOTV (@whiotv) August 20, 2015

Goslee responded to questions about whether Noah and his sister should have been returned to Pilkington.

“The court found there was insufficient evidence to justify keeping the children out of the home because there was no evidence of foul play at the time,” said Goslee. “You cannot predict behavior that is so erratic. Did the system fail? The system failed to see the unforeseeable. … It’s a damn shame.”