Judge Robert Morin sentenced Sosefina Amoa to four years in prison and called the case a
Judge Robert Morin sentenced Sosefina Amoa to four years in prison and called the case a "tremendous tragedy".Reuters

A novice nun who killed her newborn baby son at a Washington DC convent has been sentenced to four years in prison.

Sosefina Amoa, 26, was sentenced at the Washington DC Superior Court on Friday after pleading guilty to voluntary manslaughter in February.

Amoa said she did not realise she was pregnant before giving birth in her room at the Little Sisters of the Poor Convent in October last year. As part of a plea deal, she confessed to smothering her newborn son by holding a piece of wool over his nose and mouth.

Her lawyer said Amoa panicked after the baby was born and had only intended to quieten the child while deciding what to do.

Weeping through much of Friday's hearing, Amoa told the judge that she was "shocked" when she gave birth. "I was not able to think straight," she said.

Prosecutor Cynthia Wright, who requested a five-year sentence, painted a grimmer picture. "The hard truth is that she consciously killed her son," she said.

Wright held up a large photo of Amoa's baby and asked the courtroom to remain silent for two minutes – the same length of time that Amoa said she placed her hand over her son's mouth and nose.

Amoa's lawyer Judith Pipe dismissed the request as "theatrics", but Judge Robert Morin allowed the pause to go ahead.

Morin said the case was a "tremendous tragedy" and that he believed Amoa had been in denial about her pregnancy.

The judge added that Amoa had led a good life before killing her son and said that he believes she is committed to leading a good life once again. "I hope you do heal," he told her.

Amoa had arrived in the US from her native Samoa less than a week before delivering the baby. Her lawyer said Amoa would have never travelled to the US if she knew she was pregnant, and never intended to hurt her baby.

Pipe said Amoa should not spend any more time in prison and should instead be immediately deported to Samoa. Alternatively, Pipe said a sentence of less than a year was appropriate.

Nuns from the Two Little Sisters of the Poor Convent attended Friday's hearing, but declined to comment.