A St. Louis woman is facing murder charges for allegedly smothering her newborn twins ? and then lying about it to police, authorities said.

Maya Caston, 25, claimed to St. Louis County police on Wednesday that she unexpectedly went into labor and that the babies were stillborn. Responding officers then found the baby boy and girl dead at the scene, KSDK reported.

A subsequent investigation, however, revealed that the babies had been carried to full term and that neither was stillborn, court documents show.

?She covered their mouths and noses with a towel and blanket, concealed them, and failed to see medical attention,? a probable cause statement reads. ?Both babies died as a result.?

Caston gave birth to the infants sometime between Jan. 6 and Wednesday, authorities said.

While acknowledging that the infants could have died from a medical event, police said Thursday that their deaths had been reclassified as suspicious, the Riverfront Times reported.

Caston was arrested Saturday on two counts of second-degree murder and two counts of abuse or neglect of a child. She was jailed on $500,000 bond.