The Clark County Department of Family Services confirmed that the 2 1/2-year-old was found by his father's girlfriend Tuesday morning, and he was not breathing and had multiple bruises.

The hearing was held to determine whether Zander's three siblings should return to their father's care while authorities investigate Zander's death.

Sullivan, citing the seriousness of the child's death, ordered them kept in protective custody at Child Haven, the county's temporary shelter for abused and neglected children.

The county removed the children from their father's home after Zander was found dead.

During the hearing, Zander's birth mother, Joanna Jackson, who lives in Oregon and was speaking to the court by telephone, said she sent a letter three weeks ago to county caseworkers warning them that the children might be in danger if they remained in their father's home.

The county confirmed that Jackson sent the letter but said it didn't contain warnings about the children's safety, said Christine Skorupski, spokeswoman for county family services.

Richard "Todd" Martino, the children's father, appeared in court with his live-in girlfriend but remained mostly silent throughout the hearing. He left the courthouse without speaking to reporters.

The coroner's office hasn't determined how Zander died and Las Vegas police still are investigating the case. Authorities haven't charged anyone with a crime in connection to the death.

Zander was found in the family's home in the 200 block of Hoover Avenue, near Main Street and Bonneville Avenue.

The county said it investigated the Martino household five times on suspicion that the parents abused or neglected the children. The parents were found responsible for abusing or neglecting their children -- once on Dec. 9, 2004, and again on May 4, 2006, according to county records.