Sergio Hernandez, 40, and Joslia Williams, 18

More information has surfaced regarding the death of the 15-year-old girl from Chicago whose body was found in an Oak Park alley the morning of Saturday, Aug. 7.

During the couple’s bond hearing at the Maybrook courthouse on Aug. 10, a Cook County prosecutor detailed the victim’s final hours, which were allegedly recorded by defendants in a series of videos posted on the social media app Snapchat.

According to the prosecutor’s bond proffer, the teenager was drugged and raped over a period of hours beginning on the night of Aug. 6 before her body was discarded in an alley behind the 200 block of North Taylor Avenue.

Sergio Hernandez of the 3100 block of North Austin Boulevard, has been charged with criminal sexual assault, aggravated criminal sexual abuse and concealment of a death.

Joslia Williams, 18, of the 1700 block of Menard Avenue, was charged with child pornography and concealment of a death. Hernandez and Williams are each being held in Cook County Jail on $500,000 bond.

The bond proffer states that, prior to the teenage girl’s death, she was drinking and smoking cannabis with an unnamed witness and Williams, who had been posting videos on Snapchat throughout the night, in Hernandez’s car in Chicago the evening of Aug. 6. 

The girl and Williams then reportedly took pills, suspected to be Xanax, while at a beach on the South Side of Chicago. After dropping off the unnamed witness at around 11:30 p.m., said the prosecutor, Hernandez continued to drive around with the victim and Williams, until Hernandez, who had identified himself in one of the videos, pulled over and raped the victim while Williams recorded it on Snapchat.

Two other videos reportedly showed the victim as visibly unconscious. Williams and Hernandez reportedly fell asleep in Hernandez’s car, with the girl lying unconscious in the backseat, for several hours. When they woke up and realized the victim was not breathing, they reportedly attempted to resuscitate her without success.

Hernandez then drove around before pulling into an alley as Williams redressed the victim’s body. Hernandez then allegedly removed the victim from the car, placed her in the alley and left the scene.

A resident discovered the body and called police at 8:30 a.m. on Aug. 7. The girl was pronounced dead on the scene by Oak Park paramedics, who responded to the call with police. She had been reported missing to the Chicago Police Department about three hours after her body was found.

According to the bond proffer, the victim’s mother saw one video showing Hernandez trying to push the unconscious victim from the front seat to the back seat of Hernandez’s vehicle.

The girl’s family then reportedly located Hernandez and recorded him on a cellphone making statements about leaving the girl’s body in an alley. Chicago police arrested Hernandez. Oak Park police later arrested Williams.

The Cook County Medical Examiner has not yet determined the cause and manner of the girl’s death, which is pending the results of a toxicology report.