Authorities seek a motive in mass shooting at an Idaho In-N-Out Burger

Investigators are trying to determine what led a 24-year-old man to open fire at an Idaho fast-food restaurant over the weekend, in an attack that left three people dead and seven others wounded before authorities say he killed himself.

Investigators are trying to determine what led a 24-year-old man to open fire at an Idaho fast-food restaurant over the weekend, in an attack that left three people dead and seven others wounded before authorities say he killed himself.