An Oregon woman was charged with murdering a 21-year-old expectant mother and her unborn baby after faking her own pregnancy.

Korena Roberts, 28, of Washington County, is being held without bail Sunday after allegedly killing Heather Snively — whose body was found in the crawlspace of a house in Cedar Hills, Ore., according to the Washington County Sheriff's Office.

The nearly full-term fetus also died.

Snively's cause of death wasn't immediately known, and it was unclear how the baby was extracted from the womb, according to FOX affiliate KPTV.

Deputies said Roberts pretended to have just given birth. She and a man called 911 Friday to say the baby was not breathing.

When police arrived on the scene, a man was administering CPR to the newborn, Washington County Sgt. David Thompson said in a press release.

Rescuers sent the baby and Roberts to a hospital, where it was determined that she had not recently given birth.

Deputies searched the house and found Snively dead.

Roberts' neighbors said she told them she was expecting a baby.

"She had told my mother about a week ago that she was pregnant — about to have a baby — like seven or eight months pregnant," Doug King told KPTV. "She didn't appear to be pregnant to us. She had gained weight, but not a lot in the belly or anything like that."

The victim's boyfriend and father of the baby reported her missing and said she was in the third trimester of pregnancy.

Click here for more on this story from FOX affiliate site KPTV.com.

The Associated Press contributed to this report.