A friendship that once brought two families together ended in tragedy after a California doctoral student admitted to killing her best friend’s six-week-old son while caring for him in Pennsylvania. The infant’s twin brother was also injured, and the case has left the children’s parents facing a loss they say will affect them for the rest of their lives.
Nicole Elizabeth Virzi, 32, pleaded guilty on October 28, 2026, in connection with the June 2024 death of Leon Katz and injuries suffered by his twin brother, Ari. Under the plea agreement, she avoided a potential death sentence and was sentenced to serve between 35 and 80 years in state prison.
The case unfolded in Pittsburgh, where Virzi had been visiting the family. What initially appeared to be an emergency involving a baby who had reportedly fallen became a criminal investigation that uncovered serious injuries to both infants.
How a Night of Babysitting Turned Into a Tragedy
On June 15, 2024, Leon’s parents asked Virzi to care for their newborn son while they took his twin brother, Ari, to the hospital.
According to investigators, the parents had become concerned after an injury was discovered in the area of Ari’s genitals. Medical examinations later raised concerns about injuries to both children.
While Leon remained at home with Virzi, she eventually called 911 shortly before midnight, reporting that the baby had fallen from a bassinet and struck his head.
Leon was taken to a hospital, where doctors tried to treat his injuries. However, the six-week-old infant died several hours later, on Father’s Day.
The initial explanation prompted further investigation as doctors assessed the extent and nature of the injuries. Medical findings described in court documents included a severe skull fracture and multiple brain bleeds.
Investigators also learned that Virzi had been the only person caring for Leon during the period in which the fatal injuries occurred.
Doctors Found Injuries to Both Twins
The investigation expanded after medical professionals examined both children.
According to the case records, doctors determined that the twins had injuries consistent with inflicted trauma rather than ordinary accidents. Leon’s injuries were described as acute, meaning they were recent.
Ari survived, but the injuries he sustained also became part of the criminal case against Virzi.
The findings raised serious questions about the explanation that Leon had simply fallen from a bassinet. Investigators questioned Virzi about how such a fall could have resulted in the injuries documented by medical staff.
During questioning, Virzi initially described falling asleep while Leon was in a baby bouncer. She said she later woke up, noticed the baby was no longer secured in the seat and went to the kitchen to prepare a bottle.
She claimed that she heard screams while in the kitchen and found Leon on the floor with a bump on his head. She then contacted the child’s parents and emergency services, according to the affidavit.
As detectives continued questioning her about the medical evidence, her account changed.
What Virzi Told Detectives
According to court documents, Virzi eventually admitted to deliberately harming Leon.
She told investigators that she had experienced what she described as an urge to hurt children from a very young age. She also said she had become angry during her visit because she felt she was being expected to perform childcare duties.
Virzi reportedly described feeling increasingly resentful about being placed in the role of a babysitter.
She admitted to shaking Leon forcefully and dropping him multiple times. She also described turning him upside down and dropping him onto the bathroom’s tiled floor.
According to the affidavit, she said she heard a cracking sound afterward.
The admissions became central to the case, contradicting her earlier explanation that the injuries resulted from an accidental fall.
The prosecution ultimately pursued criminal charges based on the fatal injuries to Leon and the harm inflicted on his twin brother.
A Friendship That Ended in Court
Before the tragedy, Virzi had been considered a trusted friend of the family. That relationship made the case especially painful for Leon’s parents.
Savannah Roberts, Leon’s mother, described Virzi as her former best friend during the October 28 court hearing. She also delivered an emotional victim impact statement about the effect the killing had on her life and her ability to feel safe.
Roberts said the loss had fundamentally changed her, leaving her struggling with grief, fear and the consequences of placing trust in someone she once considered close.
She also spoke about the lasting impact on both twins’ lives. Although Ari survived, his future will be shaped by the loss of his brother and the circumstances surrounding the injuries he suffered as an infant.
For the family, the case was not simply about a criminal conviction. It was also about confronting the death of a child who had barely begun his life.
Why Prosecutors Agreed to a Plea Deal
Before the agreement was reached, prosecutors had planned to seek the death penalty if Virzi were convicted of first-degree murder.
The case had been scheduled to proceed to trial, but the defense had sought additional time, citing the substantial preparation required for a capital case.
Ultimately, prosecutors agreed to a plea arrangement that allowed Virzi to avoid a potential death sentence.
The decision was made after consultation with the family and consideration of the emotional toll that a lengthy trial could impose, according to statements made by the prosecution.
For families affected by violent crimes, a trial can require repeated exposure to painful evidence, testimony and memories. A plea agreement can spare relatives some of that process while still resulting in a lengthy prison sentence.
However, such agreements can also raise difficult questions about accountability and the punishment a defendant should receive.
In this case, the agreement resulted in a prison sentence of 35 to 80 years.
What the Sentence Means
Virzi’s sentence reflects the seriousness of the crimes to which she pleaded guilty. The lengthy term means she will spend decades in prison, with the minimum and maximum periods governed by the sentence imposed by the court.
Pennsylvania law permits a maximum prison term of 40 years for third-degree murder. The overall 35-to-80-year sentence also reflects the additional offenses included in the plea agreement, rather than the homicide count alone.
The resolution brings the criminal proceedings to a significant point, although it cannot undo the harm suffered by the children or their family.
The case also highlights the importance of carefully investigating unexplained injuries in infants, who cannot describe what happened to them. Medical examinations, emergency records and consistent accounts from caregivers can be critical in determining whether an injury was accidental or the result of abuse.
A Family Left to Face the Future
For Leon’s parents, the loss reaches far beyond the courtroom. Their surviving son, Ari, will grow up without his twin brother, and the family must navigate future milestones while living with the knowledge of what happened.
The case is a devastating reminder of how vulnerable very young children are and how much responsibility rests with the adults entrusted with their care.
Virzi’s guilty plea and prison sentence provide a legal resolution to the case, but they do not erase the grief of losing a child at just six weeks old.
For Leon’s family, the challenge now is to continue forward while carrying a loss that will remain part of their lives for years to come.
