PhD student Nicole Virzi remains in custody on charges of homicide, aggravated assault, and endangering the welfare of children.

While visiting friends in Pittsburgh, Virzi cared for 6-week-old twins to give the mother a break. Both boys ended up in the hospital, and one died. EMTs transported Leon Katz and his father to the hospital shortly before midnight, but Nicole Virzi did not stay long.

She was seen returning to her Airbnb just before 1 a.m., struggling to unlock the door. By 5 a.m., Virzi appeared to be preparing to leave town. Security footage captured her making what seemed to be a hasty exit less than five hours later.

Although she was booked for two more nights at the apartment, Virzi appeared to be leaving. She was seen on security video leaving the building at 5:45 a.m. She reached for her phone and made a call while standing on the sidewalk.

At 5:47 a.m., Leon Katz was pronounced dead. Three minutes later, at 5:50 a.m., police arrived at the Airbnb, and two officers approached Virzi on the sidewalk, quickly placing her in a patrol car. She was then transported to police headquarters, where she agreed to questioning without an attorney present.

Joining Nancy Grace today:

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[Feature Photo: Nicole Virzi/Allegheny County Jail and Ari and Leon Katz/GoFundMe]