New York police are searching for the man who used a knife to stab two young children as they were on their way to get ice cream in East New York, Brooklyn on Sunday evening.

Officials say that the suspect stabbed the children inside of an elevator located in the Boulevard Houses on Schenck Avenue around 5:50 p.m. Police confirmed that 6-year-old Prince Joshua "PJ" Avitto died after being stabbed in his torso. The other victim, a 7-year-old girl identified as Mikayla, is currently in critical condition at Brookdale Hospital after also being stabbed in her torso, reports AM New York.

Community Activist Tony Herbert said that the stabbing seemed to be unprovoked.

PJ's father, Nicholas Avitto, told reporters that his son loved basketball and pretending to be a super hero. He would have turned 7 on June 17.

"I'm going to miss my beloved baby son," Avitto, 56, said. "I'm trying to stay strong. It's a shame, he took my little boy away from me."

PJ's mother, who remains anonymous, called for the arrest of the man who did this while visibly shaking and crying.

"No parent should have to go through this. He killed my baby," she said as she collapsed into a friend's arms outside the hospital, reports NBC New York.

NY Police Commissioner Bill Bratton said Monday that investigators are working on a sketch of the suspect, described as a heavy-set African-American man wearing a gray sweatshirt.

Bratton also said it's possible that the suspect may have also stabbed 18-year-old college student Tanaya Copeland to death a few blocks away Friday night.

He described Copeland's family as "extremely distraught," adding that "this was a good kid. This wasn't one of those kids who was out there doing anything stupid."

Investigators are currently reviewing a grainy video of that stabbing.