Tallgrass / Sandra Dallas.

Enhanced descriptions from Syndetics:

An essential American novel from Sandra Dallas, an unparalleled writer of our history, and our deepest emotions...

During World War II, a family finds life turned upside down when the government opens a Japanese internment camp in their small Colorado town. After a young girl is murdered, all eyes (and suspicions) turn to the newcomers, the interlopers, the strangers.
This is Tallgrass as Rennie Stroud has never seen it before. She has just turned thirteen and, until this time, life has pretty much been what her father told her it should be: predictable and fair. But now the winds of change are coming and, with them, a shift in her perspective. And Rennie will discover secrets that can destroy even the most sacred things.
Part thriller, part historical novel, Tallgrass is a riveting exploration of the darkest--and best--parts of the human heart.