Stephanie Rochester of Superior was arrested about 6 p.m. Tuesday on charges of first-degree murder and child abuse resulting in death. She is being held at the Boulder County Jail in lieu of a $750,000 bond.

Police say the baby, Rylan Rochester, was brought to Avista Hospital by his parents after they found him non-responsive in his crib around 6 a.m. Tuesday.

Hospital workers tried to resuscitate him, but he was pronounced dead shortly after his arrival at around 6:45 a.m.

Investigators say the ruling on the cause of death from the Boulder County Coroner's Office makes them believe it was a homicide. They did not release the cause of death, but did say the death was intentional.

9NEWS spoke with a neighbor of the Rochesters and she says she believes Stephanie Rochester had postpartum depression.

"I'm in shock. I know that she had some postpartum depression. It didn't seem terrible. So if this is true, her postpartum got really bad really fast and she turned into someone she's not on an everyday basis. She's a very sweet woman and she loved her baby. He was cared for and loved and cuddled. He had a very good life every day," Heather Craig said.

Dr. Susan Heitler is a clinical psychologist at Rose Medical Center. She says there are different levels of postpartum depression. She estimates about 20 percent of women feel depressed several days a week.

A small group has a deeper depression and a "miniscule" number go into psychotic episodes, according to Heitler.

She says it is possible to hide the extent of the pain.

"Some people who are in many ways healthy, have that ability to carry on even though inside they're suffering," Heitler said. "If the psychosis is a paranoid psychosis, the way paranoia works is a person fixates, 'He's my problem, she's my problem; the baby is my problem.' Once they get that answer, the answer, the scapegoat actually enables them to function better in the rest of their lives."

"I don't know what happens with postpartum, I didn't really have it, but it's real and whatever it is it changed, can change people," Craig said. "Because I think who she was as a mother on an everyday basis was a wonderful person who would never hurt her child."

Heitler says even though our natural inclination is to shy away from the situation, if anyone ever says, "I'm gonna kill you, I'm gonna kill myself," you should ask more questions.

She adds that if a new mom feels sad for more than a few days, they should get help. One talk with a professional counselor can help.

If convicted of first-degree murder, Rochester faces a mandatory life sentence or the death penalty. If convicted of child abuse resulting in death, the punishment range is eight to 24 years.

Investigators say they do not know if the child had been treated in the hospital before or had any prior injuries.

(KUSA-TV © 2010 Multimedia Holdings Corporation)