(CNN) -- Authorities identified 18-year-old Kia Johnson as the woman found tied up with her uterus cut open inside a Pennsylvania apartment, the Allegheny County Medical Examiner's office said Sunday.

The medical examiner says the body found in a Pennsylvania apartment is that of Kia Johnson.

Authorities used dental records to confirm the woman's identity.

Johnson's partially eviscerated body was found at the apartment of a Wilkinsburg, Pennsylvania, woman who arrived at a hospital with a newborn infant earlier in the week.

A placenta was found at the scene, the Allegheny County, Pennsylvania, medical examiner said.

Johnson's body "was in a state of moderate decomposition" and the woman had been dead for about two days, Medical Examiner Karl Williams said in a written statement.

Johnson's hands and feet were bound by duct tape. The cause of death remains undetermined, Williams said.

Drugs were found at the scene, and authorities are awaiting toxicology results to determine whether the woman was sedated, he said. It's unclear whether the woman was alive when the infant was taken, he added.

The body was found Friday at an apartment belonging to a woman with a history of attempting to steal newborns, according to court records obtained by Pittsburgh Tribune-Review.

Andrea Curry-Demus, 38, is charged with endangering the welfare of a child, a felony, and dealing in infant children, a misdemeanor. Court records show that she was arraigned on the felony charge Friday and is next set to appear in court on Thursday. She is being held at the Allegheny County Jail, WTAE reported. Watch Andrea Curry-Demus being taken into custody »

According to a criminal complaint, Curry-Demus was taken by ambulance to a local hospital Wednesday with the baby, claiming it was hers. Tests at the hospital proved that she was not the mother, and police were notified.

Curry-Demus told Grande she had suffered a miscarriage in June and "did not want her mother to get upset."

In the complaint, Detective Rich Grande said Curry-Demus told him she purchased the baby from a woman named Tina for $1,000. Morton said fingerprint testing had ruled out a woman named Tina Carter, one of two other pregnant black women who have been reported missing in the area.

Don't Miss WTAE: Autopsy provides clues

On Wednesday, Curry-Demus said, Tina showed up with her newborn wrapped in a towel and left. Curry-Demus said she called medics because the baby was still "dirty from birth," the complaint said.

The baby is in good condition, a hospital spokeswoman said, and will be released to child welfare workers when he is ready.

Reporters visiting Curry-Demus' apartment earlier Friday had noticed flies and smelled an odor from the sidewalk below, WTAE said. Police Chief Ophelia Coleman said the body was not found earlier because Curry-Demus' sister led them to another apartment.

Friends and relatives said Curry-Demus had told them she was pregnant for months, even having a baby shower.

"I went to the baby shower and her wedding," Ivee Blunt said. "I had no idea something like this could happen. I'm totally shocked. And she was so nice and kind. It's just unbelievable."

But Stephanie Epps, Curry-Demus' sister-in-law, said Curry-Demus would never allow her to touch her stomach.

"Pregnant women do things like that," she said. "They're happy because they're pregnant. But she would never do none of that."

As she was led out of the Wilkinsburg Police Department, Curry-Demus told reporters, "I didn't do nothing," according to WTAE.

According to court records obtained by the Pittsburgh Tribune-Review, Curry-Demus became pregnant at 12 and miscarried four months later. She had a second miscarriage in 1990, when she was 21, the paper said.

Only a few months after the second miscarriage, Curry-Demus befriended a woman who had just given birth but later attacked her with a knife and tried to steal the baby, the paper said, citing the court records.

The woman's husband intervened, and she fled, the newspaper reported.

The next day, she went to a hospital and befriended a woman who had brought her 3-week-old daughter to the hospital to be treated for meningitis, the Tribune-Review said.

When the woman went home for the night, Curry-Demus left the hospital with the baby. It was found at her home, unharmed, the following day.

In 1991, according to the records, she pleaded guilty to various charges stemming from both incidents and was sentenced to three to 10 years in prison, the newspaper reported.

She was paroled in August 1998 and ordered to serve 10 years of probation, the paper said.

Curry-Demus was examined by psychiatrists at the Allegheny County Jail before her sentencing and was diagnosed with severe depression, personality disorders and auditory hallucinations, the newspaper reported, citing court records.

She told doctors she spent a lot of time thinking about her miscarriages and "kept hearing babies cry," the Tribune-Review said.

Wilkinsburg is just east of Pittsburgh, Pennsylvania.

Earlier this year, a Kansas woman was sentenced to death in the 2004 killing of a Missouri woman whose baby was cut from her womb.

Lisa Montgomery was convicted in October in the death of Bobbie Jo Stinnett, 23, who was found strangled in her Skidmore, Missouri, home. Stinnett's womb was cut open, and her unborn child was missing. Montgomery was found days later at home in Kansas, where she was attempting to pass the baby off as her own.

CNN's Christina Chinnici and Janet DiGiacomo contributed to this report.

All About Pregnancy and Childbirth • Pennsylvania