KALAMAZOO, Mich. (AP) — A 38-year-old western Michigan man has been charged in the death of his girlfriend’s 7-month-old son.

Sonny Larsen was arraigned this week on murder and first-degree child abuse charges.

The child’s mother called 911 after finding him unresponsive Wednesday in her Kalamazoo apartment, southeast of Grand Rapids. He later was pronounced dead at a hospital.

Police said an autopsy showed the infant suffered head and neck trauma.