A Superior woman was arrested Tuesday night on suspicion of killing her 6-month-old son.

Stephanie Rochester, 34, a mental-health counselor at Children's Hospital in Aurora, was being held on $750,000 bail in the Boulder County Jail.

She was arrested on a warrant alleging first-degree murder and child abuse resulting in death.

She and the boy's father brought Rylan Rochester to Avista Hospital in Louisville about 7 a.m. Tuesday, saying he was found unresponsive in his crib.

The Boulder County Sheriff's Department did not disclose the cause of death. The father, Lloyd Rochester IV, had not been charged.

Neighbor and close friend Heather Burris told the Boulder Daily Camera that Stephanie Rochester "had a little bit of postpartum depression."

"She had mentioned it, but it was nothing that stood out to me," she said.

Another neighbor, Kimberly Rouland, told the paper that Rochester had complained about a lack of sleep since Rylan was born in November, but she "adored her child."

"I'm just sick and heartbroken for her and her family."

Neighbor Tami Warmen said: "I don't think anyone could say anything bad about them. They were just the most wonderful couple."

Autopsy results had not been released Tuesday.

Boulder County District Attorney Stan Garnett told the Daily Camera that his office will review the matter closely.

"The Sheriff's Office has informed us that there is evidence to establish that the death was intentional," he said.

Public records show Stephanie Rochester has lived in Colorado since 1996, with previous residences in Littleton, Boulder and Algonquin, Ill. Records indicate her immediate family lives in Illinois.

Attempts to reach them were not successful. She and her husband bought the home in Superior in December 2008, according to public records.

She has a bachelor's degree in psychology from the University of Colorado at Boulder and is working on a master's degree at Regis University, according to her page on the LinkedIn social network.

Source: Joey Bunch, "Superior mom held in death of 6-month-old son," Denver Post, June 2, 2010.