Sosefina Amoa told District of Columbia police she didn't know she was pregnant when she gave birth Oct. 10 at the Little Sisters of the Poor convent, The Washington Post reported Friday.
She had arrived in the United States Oct. 5 to join the order.
Amoa, 26, said she smothered the child with a wool garment so the nuns wouldn't hear the baby cry and know that she had had sexual activity.
The next day, she told a nun she had found the baby outside, but later confessed the infant was hers, police said. The nun helped her carry the baby to a hospital, where it was pronounced dead.
Amoa has been charged with first-degree murder.
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