CHICAGO (AP) — A second teenager suspected in the sexual assault of a Chicago teenager that was streamed live on Facebook turned himself in to police on Monday afternoon.

Police spokesman Anthony Guglielmi said the mother of a 15-year-old boy who was being sought on an arrest warrant issued Sunday brought him to a police station. Guglielmi said the boy would be later brought to a juvenile detention center where a 14-year-old boy who was arrested in the case over the weekend is being held.

Each teen faces felony counts of criminal sexual assault, manufacturing of child pornography and dissemination of child pornography, Guglielmi said.

Police have not provided details about what exactly happened on March 19 when they said five or six males participated in sexually assaulting a 15-year-old girl after she was lured inside a residence by one of the suspects. But they have said that besides the cellphone camera that recorded the incident and streamed it live on Facebook, others at the scene also recorded the sexual assault.

Police say they expect other juveniles and an adult to be charged. Police haven't released the names of any suspects.

Police have said the assault was watched live by about 40 viewers, none of whom called authorities to report what was happening. The girl's mother later told The Associated Press that the girl and the family were being taunted online and ridiculed and harassed by children in their neighborhood.

Police say they are investigating the online comments and have executed a number of "social media search warrants."

Police have moved the girl, whom they describe as "traumatized," to a home outside the neighborhood. In a brief interview, the girl's mother said Monday that her daughter remains at what police called the "safe place" and has not returned to school.

The AP generally does not identify potential victims of sexual assault and is not identifying the mother so as not to identify the girl.

Also Monday, a juvenile court hearing for the teenager who was arrested over the weekend was postponed until April 28.