The jury reached its verdict Wednesday in the trial of the former nanny, 55-year-old Yoselyn Ortega, who was charged with stabbing the children on October 25, 2012.
Jurors found that Ortega killed 6-year-old Lucia Krim and 2-year-old Leo Krim in October 2012 and understood the consequences of her actions when she did it.
Ortega expressed no reaction to the verdict, staring straight ahead as it was read in court. The children's father, Kevin Krim, held hands with two alternate jurors who said they would stay for the verdict and then hugged them after it was read, and they cried together.
"Today a jury rightly and finally held Yoselyn Ortega accountable for the horrific slayings of Leo and Lulu Krim," said Manhattan District Attorney Cy Vance Jr.
The judge gave final instructions Tuesday to the six men and six women, who for weeks have listened to gut-wrenching testimony, gruesome details of the murders.
After the verdict, jurors talked about the trial and its harrowing evidence. "Everyone of us individually could feel the heartbreak and the agony when they were on the stand testifying and as we watched all the rest of the things unfold," said juror David Kurtis.
Their mother, Marina Krim, had just returned from swimming lessons with her 3-year-old daughter to find them dead in the bathtub.
Ortega's attorney maintained she suffers from mental illness and severe depression, and that she lacks the capacity to form intent to kill. Prosecutors, however, say that she knew exactly what she was doing and carried out a well-planned attack.
Prosecutors said the motive was Ortega's mounting financial troubles and her deep resentment of the Krims.
Following the verdict, Kevin Krim posted a message on Facebook:
Ortega, who's from the Dominican Republic, showed little emotion during the trial and mostly stared straight ahead. But she shook her head forcefully and mouthed "no" during testimony that her employers treated her well.
Jurors heard heart-wrenching testimony from Marina Krim, who spoke of the sickening, desperate moments when she saw her children's vacant eyes, their small bodies perforated by stab wounds.
Krim was at a swimming class with her 3-year-old daughter, Nessie. They went to pick up Lucia from dance class, but she wasn't there.
Krim, after finding Lucia's and Leo's bodies in the family's home, ran outside with Nessie, called for help and started screaming.
"It was a scream you can't imagine is even inside of you," she testified. "I don't even know where it came from. I just thought: 'I'm never going to be able to talk to them ever again. They are dead. I just saw my kids dead.'"
Lucia, who was called Lulu, was stabbed more than 30 times and had defensive wounds on her body. Leo was stabbed five times.
Their father had been away on a business trip. At Ortega's trial, he spoke of walking down a long hallway at the hospital where he saw his children.
"They still had this perfect skin and these long eyelashes," Kevin Krim said. "They had like sandy brown hair. ... You could see they tried really hard to wash all the blood out, but there was still kind of an auburn tint to it that I remember to this day."
The father's testimony brought tears to the jurors and to people seated in the courtroom gallery. The father had no comment after the verdict against Ortega was read.
Ortega faces a possible sentence of life behind bars.
(The Associated Press contributed to this report.)