Glamorous PhD student, 29, 'who tortured friends' baby to death while babysitting him' is warned she faces ultimate punishment if convicted

A glamorous PhD student faces execution if she's convicted of murdering her friend's six week-old son while babysitting him, prosecutors say.  

Nicole Virzi, 29, has been charged with murdering six-and-a-half-week-old Leon Katz while she babysat him at the family's Pittsburgh home in June.

Police allege she is responsible for inflicting a fracture to his skull and several bleeds on the brain picked up by a CT scan. She's also accused of injuring Leon's twin brother Ari, who survived. 

Court documents obtained by WPIX show the Allegheny County District Attorney’s Office is seeking the death penalty against Virzi.

The filing, which laid out the reasons for seeking the death penalty, reads: 'The defendant committed the killing while in the perpetration of a felony. The offense was committed by means of torture.'

'The defendant has a significant history of felony convictions involving the use or threat of violence to the person. The victim was a child under 12 years of age.'

Further details of these previous convictions were not shared. A public records check for Virzi only showed up details of the charges she faces over Leon's killing.  

Virzi was a 'trusted friend' of the babies' parents Ethan Katz and Savannah Roberts who was watching the twins while on her college break. 

Her father, Peter J Virzi, is a top cardiologist affiliated with Mt. Sinai Doctors in Manhattan and is certified by the American Board of Internal Medicine. 

The accused killer was continuing to babysit tiny Leon while his parents were at UPMC Children's Hospital of Pittsburgh with his twin, Ari, after Virzi said she spotted an injury on his groin area, police said.

She told cops that she had gone into the kitchen to get the baby a bottle when she suddenly heard screaming.

When she returned she said the baby had fallen out of his bouncer chair. She then called 911.

'The injuries sustained by both (twins are) consistent with having been sustained as a result of child abuse, as these are inflicted injuries that are not natural and not accidental,' a doctor told investigators, according to court filings.

Virzi has denied any wrongdoing and her lawyer maintains her innocence. She is charged with homicide, child endangerment, and aggravated assault.

Cops have yet to share a motive for the horrific crime.  

A video posted days before the Ph.D student allegedly killed her friend's baby shows her discussing a paper she wrote about depression in women.

In the video shared by the Heart and Mind academic journal on June 13, Virzi is wearing a white blazer and comes off well-spoken as she delves into how somatic symptoms of depression in women can lead to risks of heart disease.

A GoFundMe set up for the devastated couple says Leon was 'tragically killed under horrific circumstances' and that a 'trusted family friend' has been arrested.

'Leon will always be remembered as a happy, smiley, goofy baby boy. His untimely and tragic death has deeply impacted the Pittsburgh community,' the donation page said.

Pictures taken just days before the tragedy showed the bright-eyed twins side by side in onesies with their names embroidered on them.