One youth said of the older suspect: "He's real cool.
On 30 October, the 64-year old suspect was released from custody.
The suspects, 13 to 16 years old, are all residents of the neighborhood where the assault occurred.
They ran checks on old suspects and talked to old detectives.
The 21 year old suspect is an American who converted to Islam.
The search for an older suspect was unusual and narrowed the field, the chief said.
The police later arrested a 17-year old suspect and charged him with murder.
"It's fresh ideas about old suspects that I'm after," he finally said, and started for the door.
But at the police station, the Post reported, the older suspects "were screaming over each other to proclaim their innocence."
The oldest suspect is a 61-year-old woman, while the youngest, from another family, is a 16-year-old boy.