New York (CNN) -- A New York man released on parole last month pleaded not guilty Wednesday in connection with the stabbing of two children in Brooklyn, one of whom died, authorities said.
Daniel St. Hubert, 27, was indicted on charges of second-degree murder, second-degree attempted murder, first-degree assault and criminal possession of a weapon. He faces 50 years to life in prison if convicted.
Police believe Hubert was out on parole on June 1 when he allegedly stabbed the two children -- killing one of them -- inside an elevator.
"These two innocent children were subjected to unimaginable violence and terror in that elevator," Kings County District Attorney Kenneth Thompson said in a statement. Prince Joshua "PJ" Avitto, 6, died from his injuries, and his friend, Mikayla Capers, 7, was wounded.
St. Hubert was arrested one week ago around the same time that New York Police Chief of Detectives Robert Boyce identified him by name publicly for the first time as the suspect in the attack.
St. Hubert has at least nine prior arrests, though police did not specify all the outcomes.
The most recent outcome was May 23, when, Boyce said, St. Hubert was released on parole in connection with a domestic assault case.
Nine days later, police believe he encountered PJ and Mikayla inside an elevator at a public housing complex in Brooklyn. Mayor Bill de Blasio said last week that the two children were "on their way to get ice cream" at the time.
For reasons authorities haven't yet explained, both children were stabbed in the torso. PJ was transported to a nearby hospital, where he was pronounced dead. "These parents are in such pain now," de Blasio said.
Police initially said Mikayla was in critical condition. But the mayor last week said: "She's doing much better. She's a strong young lady." A spokesman for New York-Presbyterian Hospitals has refused to comment on her condition. Mikayla was treated for abdominal bleeding and a lacerated spleen, prosecutors said.
A knife believed to have been used in the attacks was recovered at the scene. The bloody knife later tested positive for the defendant's DNA, authorities said.
Avitto was related to Taj Gibson, a forward for the Chicago Bulls. Gibson tweeted last week: "They killed my lil super man. #rippj only two more weeks until your 7 birthday. Tears forever." Gibson also posted a picture of Avitto to his Instagram account.