Dad Kevin Krim says it's right nanny Yoselyn Ortega (YOH'-sih-lihn ohr-TAY'-guh) "should live and rot and die in a metal case".
"I'm very sorry for everything that happened", Ortega said through an interpreter before the sentencing.
Ortega could be seen stabbing herself in the neck as she stood over the tub.
She claimed she did not remember the attack and was possessed by the devil, but a psychologist told jurors she was depressed, but not mentally ill - and had not mentioned hallucinations at the time.
Yoselyn Ortega, 56, killed six-year-old Lucia and two-year-old Leo with a kitchen knife in the bathroom of their affluent Upper West Side apartment on Oct 25, 2012.
Ortega had been working for the family for almost two years when she brought the two siblings to the back bathroom of their Upper West Side apartment and stabbed them to death.
The anxious mother arrived to every parent's worst nightmare - the gruesome sight of her dead children in a bathtub, blood everywhere, and a kitchen knife dumped in the sink. Their father was out of town.
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Ortega had pleaded not guilty on the grounds on the grounds of mental illness, but NY courts have a high bar for proving insanity, with jurors deciding she was aware of what she was doing.
The motive, prosecutors said, was Ortega's overwhelming financial problems after bringing her 17-year-old son from the Dominican Republic and her resentment toward Marina Krim, married to then-CNBC executive Kevin Krim, for being the mother "she could never be".
During the recent trial in the Supreme Court at Manhattan, the mother of this victims Marina Krim told the court the way she had come house along with her third child, three-year-old Nessie, after Ortega failed to turn upward at Lulu's dancing course. Kim said that during the investigation, neither the babysitter nor her family showed no regret over the death of children.
Ortega was convicted last month in the 2012 deaths of 6-year-old Lucia Krim and 2-year-old Leo Krim and faced life in prison without parole at her sentencing Monday. Ortega, a USA citizen originally from the Dominican Republic, had stabbed Lulu 30 times. Krim frantically tried to reach Ortega, who had worked for the family for about two years.
When Marina opened the bathroom door, Ortega, who had slit her wrists earlier, stuck a knife into her own throat.
"It's the people of NY who wrapped their arms around us in our darkest moment - they are what make this the greatest city in the world", he said.
Ortega stabbed Leo five times and Lucia 30 times, according to testimony from an assistant medical examiner.
The Krims spoke of how Ortega robbed them of their children and how Ortega's family and friends helped with this by lying to them about Ortega's personality and experience as a nanny.