CIRCLEVILLE, Ohio – Authorities in central Ohio are searching for a man who is accused of causing fatal brain injuries to his girlfriend’s 10-month-old baby.

The Pickaway County Sheriff’s Office said Friday that 44-year-old Wayne Martin Walker might already have left the state. A warrant charging him with murder has been issued.

Deputies said Walker lived with the baby’s 24-year-old mother in Laurelville, south of Columbus. She called 911 early Wednesday to report that her infant son was unresponsive.

The child suffered injuries consistent with shaken-baby syndrome. He died at a Columbus hospital Thursday.

The sheriff’s office said Walker is from California and moved to the area several months ago. He was believed to be traveling south through Kentucky.