CHEYENNE -- A Riverton mother of three young children is being held on a charge of first-degree murder for allegedly strangling her newborn baby shortly after giving birth.

A Fremont County circuit court judge set bail at $500,000 on Friday for 21-year-old Lorene Quist Gines. The judge scheduled a preliminary hearing for Thursday.

Riverton police Sgt. Victor Matoon said Gines left her mother's house and gave birth to a baby girl in a camper on the property last Tuesday morning. Gines' pregnancy had reached its full term, according to a police affidavit.

"Gines had apparently been pregnant and hid her pregnancy from others," Matoon's affidavit said. "Furthermore, she did not seek any prenatal care for her unborn child."

Gines told police the baby was born dead with the umbilical cord around its neck, according to the affidavit. She said she tied a string around the umbilical cord to cut the cord and then put the baby's body in a plastic bag and returned to her mother's house.

Gines tried to clean herself up without telling anybody about the birth, the affidavit said. But her mother, Pennie Hughes, confronted Gines because of her heavy bleeding. Gines then pointed Hughes to the baby's body, and Hughes called 911 for help.

Police say a pathologist conducting an autopsy found a string tied around the infant's neck. He also found that the baby's lungs had been oxygenated before death, meaning the baby was born alive and had drawn breath, according to the affidavit. The pathologist ruled the death a homicide caused by ligature, strangulation and suffocation.

A first-degree murder conviction is punishable by death or life in prison. A public defender representing Gines did not return a phone call seeking comment on Monday.

Hughes, Gines' mother, is caring for Gines' three other children, ages 1, 2 and 3, Matoon said.

Two days after the alleged crime, Matoon interviewed Gines at Riverton Memorial Hospital. Gines said she may have strangled the baby, but did not remember doing so, according to the affidavit.

"She did admit to me that she didn't want the baby because she couldn't afford to care for the baby, and she had considered giving the baby up for adoption but had never contacted any agency or doctor that could assist her," Matoon said.