PHOENIX, AZ (KPHO/KTVK/CNN/WBTW) – New details are emerging in a murder case in Phoenix, Arizona.

Police say a mother has confessed to smothering her three small children to death – all of them under the age of four.

Rachel Henry was in court Tuesday, facing three counts of first-degree murder.

KPHO/KTVK via CNN

Henry’s friends in Oklahoma are trying to come to terms with how this could have happened.

“Her little boy was super sweet. He was a little shy, but he was super sweet and the last time I seen him… the little girl, well the middle child, was just born,” said a friend of Henry, who didn’t want to be identified.

She said she was good friends with Henry in high school in Oklahoma and lost touch about a year and a half ago.

“She just never really showed emotion or really cared about anything. She was always crazy, but she never seemed like that kind of crazy,” Henry’s friend said.

Court paperwork describes a horror scene.

Henry was home with the children while their father and another relative were out.

Documents say she admitted to smothering each child, starting with the 1-year-old girl, while her 3-year-old son tried to stop it. She did the same to him, and sang to the infant as she covered her nose and mouth. Then, she laid them each down as if they were taking a nap.

Tonight, a growing memorial outside of their home.

“We’ve seen stuff happen and everything around here, but nothing like this, nothing like this. It was just terrible,” a neighbor said.

Henry appeared in front of a judge, who gave her a $3 million bond.

“I don’t have any money, i don’t have a job or anything,” Henry said.

“It’s a sizable amount, I acknowledge. I do think the size of the bond is appropriate based on the accusations we hear in these initial hearings,” a judge said.

Her friend in Oklahoma said this isn’t the girl she grew up with.

“I’m disappointed and I’m heartbroken, and I don’t understand how she could do something like that.”

Police say Henry struggled with addiction.

According to investigators, family welfare services in Oklahoma went as far as taking her kids away because of her drug problem.

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