PHOENIX -- A Peoria woman is charged with first-degree murder in the death of a 4-month-old infant she was baby-sitting, the county attorney's office said.

A grand jury indicted Lisa Kathleen Randall, 46, on Wednesday in the death of Dillon Uutela, County Attorney Andrew Thomas said.

Dillon's mother dropped him off at Randall's house on April 18. About 90 minutes later, Thomas said, Peoria police and firefighters were called to the home because the baby was unresponsive.

Dillon was rushed to the hospital and died the next day. Thomas said he suffered massive brain swelling and a fractured skull.

Thomas said evidence provided by police and the medical examiner led him to pursue criminal charges in the baby's death.

Randall was arrested Thursday morning on one count of first-degree murder and one count of child abuse.

A new report from the Arizona Department of Health Services shows an increase in child homicides statewide. Sixty-three children were the victims of homicide in 2006 statewide; 25 percent were 1 year old or younger.