Almost five years to the day since 4 1/2-month-old Jasmine Manning died in Navy housing here, her mother pleaded guilty in federal court to smothering the child to death.

Nina Manning, 27, pleaded guilty Thursday to second-degree murder in a case that the city Medical Examiner's Office initially classified as a death by natural causes, then later listed as a homicide based on evidence developed by the Naval Criminal Investigative Service.

Manning entered the plea after U.S. District Judge J. Michael Seabright earlier rejected efforts by Manning's defense attorney to suppress a confession the defendant made to naval investigators in 2005.

Manning is free on bail until sentencing in the case, scheduled for Jan. 22. Assistant U.S. Attorney Loretta Sheehan said yesterday Manning will likely be sentenced to 10 to 12 years in prison.

Defense attorney Richard Kawana said in court Manning is extremely remorseful and is undergoing therapy while still trying to cope with what she did.

In attempting to suppress the confession, Kawana argued that "at the time of the incident in 2002 as well as at the time of the interrogation in this matter in 2005, (Manning) was suffering and had been suffering from mental illness or depression."

In the confession, Manning, wife of a sailor who was deployed overseas at the time of the child's death, said Jasmine had been crying a great deal the night before and that Manning became upset and had no one to turn to for help.

In her guilty plea, Manning said she "grasped the back of (Jasmine's) head and placed her other hand over the mouth and nose" of the child.

The baby struggled, lost consciousness and stopped breathing, the guilty plea said.

Manning said she placed the child on the floor of a closet, went outside, smoked a cigarette, then returned inside and fell asleep for several hours.

She awoke about 4 a.m., opened the closet door and found Jasmine's "body was cold."

She took the baby from Radford Terrace Naval Housing to Tripler Army Medical Center, where she was pronounced dead.

The Medical Examiner's Office was given a copy of a statement from Manning saying she had found the baby unresponsive in her crib. After an autopsy, the examiner's office issued a report that "the cause of death was 'natural' based on the erroneous belief that Jasmine's lung slides showed 'pneumococcal pneumonia,' " according to legal papers filed by Sheehan.

Naval investigators obtained samples of the baby's lung tissue and sent all the medical records to the Armed Forces Institute of Pathology, which disagreed with the natural cause of death finding, according to the prosecution.

Investigators then interviewed Manning in June 2005 in Georgia and she confessed to the crime, according to court papers.

Reach Jim Dooley at jdooley@honoluluadvertiser.com.