Three boys were booked Tuesday for investigation of attempted murder in the beating of a month-old infant during the theft of a Big Wheel tricycle from a home in their neighborhood.

Authorities believe the boys, two 8-year-olds and one 6-year-old, broke into the home Monday evening while an 18-year-old stepsister was in another room.

They tipped over the baby’s bassinet, then kicked, punched and possibly used a stick to beat the child, police said.

The infant was on life support with severe head injuries at Children’s Hospital in Oakland.