Kim Zolciak's Son Kroy Biermann Jr. Released From Jail, Living Under Her Care

Kim Zolciak's son, Kroy Biermann Jr., is back home with his mother after his release from jail in his sexual battery case ... TMZ has learned.

Sources familiar with the situation tell TMZ ... KJ was released within the last several days and is now living with Kim, who has full-time care of him.

As TMZ first reported ... prosecutors in KJ's criminal case recently filed emergency docs asking a judge to order forensic interviews with "minor children." No other details were provided.

Forensic interviews are conducted by specially trained professionals, and the information gathered could potentially be used in the case.

KJ is facing several felony charges stemming from an alleged sexual assault involving a schoolmate at a local gym. He was 15 at the time of the alleged incident.

At a recent hearing, prosecutors also claimed KJ was already on probation in a previously unknown case ... with prosecutors claiming they found videos on his phone showing him having sex with an underage relative.

The court recently set KJ's bond at $200K.