Investigators are looking for a man they allege killed four relatives of a Tennessee baby who was found abandoned alive this week in sweltering heat, the Tennessee Bureau of Investigation said Thursday.

The four were found dead hours after the baby daughter of Wilson and Adrianna Williams was found abandoned Tuesday afternoon in a car seat in a “random” front yard near the Dyer County community of Tigrett, nearly a 40-mile drive southeast of Tiptonville, authorities had said.

A manhunt is underway for a 29-year-old man who allegedly killed four people and left their baby alive, Tennessee authorities said.