A Sandy juvenile who pleaded guilty to manslaughter in the death of a 2-year-old he was baby sitting was committed to a juvenile center for a 90-day observation and assessment period, a county official said.

The boy, who pleaded guilty in the April 26 death of infant Ester Ouzts, will undergo physical, emotional and medical tests at the Division of Youth Corrections, said Deputy County Attorney Ric Oddone.

The juvenile was baby sitting the infant and apparently caused head injuries to the baby when he became frustrated with the child, Sandy Police Detective Bob Wright said.

Following the three-month detention, the juvenile will be returned to juvenile court for another sentencing hearing, Oddone said.