Two separate cold cases in Fayette County -- each involving a mother murdering her child, whose body was then found in a creek -- are close to resolution.

During a news conference yesterday, Fayette County District Attorney Nancy D. Vernon said Sarah Sue Hawk, 25, of Uniontown, admitted to killing her newborn baby girl more than eight years ago.

And, in a much older case, Ms. Vernon said Glenda Masciarelli, 54, of Masontown, is expected to plead no contest today to a third-degree murder charge that she drowned her 2-year-old son Alfred Jr. 32 years ago in a Georges Township creek near her home.

In the Hawk case, the newborn was viable when the mother delivered the baby by herself inside a residence. But in June 2000, fishermen found the baby's remains wrapped inside a flannel shirt stuffed inside plastic bags, which, in turn, were placed inside a backpack. The backpack was found in 2 inches of water in Cove Run Creek in North Union Township.

Ms. Vernon said Ms. Hawk, faced with DNA evidence, admitted to state police that she had killed her baby.

Dr. Phillip E. Reilly, Fayette County coroner, said he consulted with forensic pathologist Dr. Cyril H. Wecht before ruling the newborn's death to be a homicide.

"And, in spite of our inability to precisely identify a single medical cause of death due to advanced decomposition of the body tissue," Dr. Reilly said, the death certificate will note the newborn was deprived of supportive care including warmth, nourishment and oxygen, and her abandonment was intentional, leading to "exposure to a hostile environment."

Facing charges of criminal homicide and concealing the death of a child, Ms. Hawk remains in the Fayette County Prison without bond.

Soon after the newborn's remains were found in 2000, police had questioned Ms. Hawk, who claimed she had not been pregnant.

But Trooper James Pierce, who was assigned the cold case in January 2007, said he noticed no follow-up interviews with Ms. Hawk. A sister of Ms. Hawk voluntarily provided him a DNA sample, which the New Jersey State Police Mitochondrial DNA Laboratory found to match the newborn's remains.

The Marshall University Forensic Science Center did further maternal analysis that identified Ms. Hawk as the mother.

Ms. Hawk was 16 when the baby was born.

Expressing relief, Mr. Pierce said the case had consumed him for two years.

"It was a case I always wanted to look into because it had never been solved," he said. "Without the new [mitochondrial] DNA test, we would not likely have solved it."

"Any time you solve a cold case, you are happy to bring closure to a tragic event," said Sgt. James Caccimelio, state police Crime Section supervisor,

The Masciarelli case traces back to Alfred Jr.'s death Sept. 26, 1976. Glenda Masciarelli had claimed her 2-year-old had been abducted while they were walking together in the woods near their home. Young Alfred was found drowned in 18 inches of creek water.

Mrs. Masciarelli, who remains free on $125,000 bond, had a history of mental instability and twice visited a county mental health agency, where she reportedly told a caseworker that her "zest for living went out the window" when she found out she was pregnant.

In November 2006, routine police interviews led to a vague admission of guilt, leading to her arrest. She also has admitted to police that no kidnapper was involved. Mrs. Masciarelli told police she has had memory lapses and could not dispute the charge of third-degree murder.