NORTH COAST, Calif. – Authorities say a Ukiah woman has been arrested for homicide after an investigation concluded that she killed her newborn baby in April 2018.

Yareli Diaz, 24, was taken into custody on Tuesday evening, according to Lt. Shannon Barney of the Mendocino County Sheriff’s Office.

Diaz is charged with killing her daughter, Mia Cielo Diaz, on April 3, 2018.

On that day just after 10 p.m., the Mendocino County Sheriff's Office was called to the Ukiah Valley Medical Center on the report of a suspicious death of an infant who was less than one day old, Barney said.

Barney said deputies learned the infant had been delivered by Diaz earlier that day. In Diaz's initial statement she claimed that she was unaware that she was pregnant but delivered the baby while in the bathroom at her home.

The death of the child was determined to be suspicious, as Barney said it appeared to be a health baby with no obvious cause of death, and Diaz’s statements were inconsistent. Mendocino County Sheriff's detectives were assigned to continue the investigation.

During the investigation, Barney said detectives learned Diaz delivered the child around 2:45 p.m. on April 3, 2018, but failed to render any aid or care to the child. Diaz cleaned up the bathroom in what appeared to be an attempt to conceal the child's birth from her parents.

Barney said Diaz wrapped the child in a towel, carried her to a parked vehicle and placed the child in the rear seat area and left her there before going back in the house. The outdoor temperature on that afternoon was 77 degrees Fahrenheit, according to the National Weather Service.

Diaz later went to work shortly before 6 p.m. and worked until approximately 8:45 p.m. when she left to meet a friend. Barney said Diaz then told the friend what had happened and the friend convinced her to immediately take the baby to the hospital for care.

Detectives believed between the birth and the arrival at the hospital the infant had received no care from Diaz. Barney said life-saving measures were attempted by hospital staff but they were not successful.

A post mortem examination was later conducted by a forensic pathologist and the infant was found to be a full-term, healthy female, Barney said.

In August, the Mendocino County Coroner's Office received the final cause of death from the pathologist. Barney said the cause of death was determined to be asphyxia due to the baby's mouth and nose being covered by towels and the placenta.

Detectives learned Diaz did in fact know she had been pregnant and that she had delivered a child several years before that her parents were helping her raise, Barney said.

At the conclusion of the investigation, detectives submitted the case to the Mendocino County District Attorney's Office for review and consideration of a charge of murder. Barney said the DA's Office then filed a case in the Mendocino County Superior Court and requested an arrest warrant charging Diaz with murder.

At 5:45 p.m. Tuesday, deputies responded to the 2400 block of North State Street in Ukiah and took Diaz into custody on the warrant, Barney said.

She was later booked into the Mendocino County Jail on one count of murder. Her bail was set at $500,000.