The couple recently moved to Fayetteville and is fighting extradition back to the west coast.
Neighbors say the couple lived in a Cumberland County mobile home about a month.
Neighbor Fisher lives next door. He says he spoke to the couple just about every day -- not knowing they had a dark secret in their past.
"You see them outside cleaning up and everything," Fisher said. "Wave, stay to their self. But like you say, whoever thought?"Authorities say in December 1995, police were called to the Pettresses' home in Barstow where they found Duree Pettress' nephew, 3-year-old Tycoon Graves, dead from blunt-force trauma injuries.
He was one of five siblings placed in the Pettresses' home by Children's Protective Services workers.
The Pettresses and the other children told police that Graves' 9-year-old sister had kicked her brother to death.
The girl was not charged and the case went dormant for 16 years, until this past February when the boy's siblings came forward to tell police the Pettresses had forced them to lie.
"Anything can break a case open sometimes," said Gavin MacRoberts, Fayetteville Police Department spokesperson. "From the tiny little bit of evidence, to somebody who saw something who finally decided they wanted to come forward and tell authorities."
Siblings told authorities that they witnessed their aunt cause Graves' death. They told police that the family had pizza the night before his death and that Graves sneaked a leftover slice the next day without permission, which led to the beating.
Police in California later traveled to Fayetteville and arrested and charged the Pettresses with murder.
Authorities say though Layfayette Pettress is not accused of beating the child to death, under California law he is equally responsible because he did not stop the beating.
The couple is currently refusing to waive extradition, so California authorities have to obtain a governor's or state warrant for the extradition.
An extradition hearing should be scheduled within the next 90 days in Fayetteville.