"The most important message is that we're all vulnerable to this kind of senseless crime, and it was preventable," said Mr. Rivera.

Judge Elaine L. Davis of Hudson County Superior Court ordered Mr. Settle, who was charged with criminal homicide, held on $150,000 bail. Prosecutors said they would present the case to a grand jury, which could decide whether to charge him with murder or reduce the charge to manslaughter. Juvenile Arrest Record

Mr. Settle, who wore a brown jacket with a Timberland logo over a green sweatshirt and black pants, said little during the 10-minute hearing, occasionally biting his lip. Mr. Settle had an arrest record as a juvenile, prosecutors said, but the judge would not allow details to be released.

Mr. Settle's lawyer, Adam Jacobs, complained to the judge that the arresting officers had not read Mr. Settle his rights before interviewing him, and he said that there were others involved in the attack who should be investigated. But Carmen Messano, the Hudson County Prosecutor, said at a news conference after the hearing that Mr. Settle "was the sole perpetrator."

Mr. Settle was enrolled in Synergy, a program administered by Volunteers of America, which helps older teen-agers who have troubled emotional and family histories live on their own, said Winnie Comfort, a spokeswoman for the New Jersey Division of Youth and Family Services, which finances the program.

Ms. Comfort said she was not allowed to discuss the specifics of Mr. Settle's case, including what emotional or family problems brought him to Synergy. It is not clear whether he has family in Jersey City or how long he has been in the program. Prosecutors said he had lived in Jersey City for at least three years and had been working 16 hours on weekends since July as a food-service aide at Christ Hospital in Jersey City. Overheard by Caseworker

The police interviewed Mr. Settle after his caseworker, Hawaiin Thompson, told them late Tuesday night that she had heard him relating the incident over the telephone, the police report said. A short time later, officers picked him up at his apartment at 150 St. Paul's Avenue, and at the station house, Mr. Settle was said to have recounted the sequence of events to officers.