BROOKLYN - Local leaders are calling for federal law enforcement to help search for the man who stabbed two children, killing one, in East New York Sunday.

According to police, 6-year-old Prince Joshua Avitto was killed and 7-year-old Mikayla Capers is in critical condition after being attacked in the elevator of their Schenck Avenue apartment building while going to get ice cream.

Rep. Hakeem Jeffries was among the officials who held a press conference asking for the FBI to step in and assist the NYPD. He said, "There is a psychopath who is on the loose, who could strike again at any moment. That is why we need all hands on deck."

Authorities released a sketch of the person believed to be responsible, and the father of the little boy says he recognizes him. The suspect is described as a heavyset black male between 25 and 30 years old, and standing about 6 feet tall.

There were no cameras in the elevator or building to capture an image of the children's attacker. A spokesperson for the New York City Housing Authority said they will be installing security cameras at developments that have received funding for them, but council members say that may not happen until the end of the year.

Mayor Bill de Blasio says he is aware of the lack of security cameras where the children were stabbed and says it stemmed from "unacceptable bureaucracy" at NYCHA.

The stabbings were just blocks away from where 18-year-old Tanaya Copeland was fatally stabbed Friday. Police confirm they've identified several common factors between the cases, including the type of weapon used.

A reward for information leading to an arrest has been raised to $12,000. Anyone with information should call Crime Stoppers at 1-800-577-TIPS.

Loved ones say the funeral for Avitto is planned for Friday. Residents have set up a memorial with flowers near the apartment building that he lived in.

Grief counselors will be available for classmates of the two children.