Prosecutors say Colin Gray is criminally culpable after his teenage son killed two students and two teachers with a rifle that had been a Christmas gift.

The greatest impact is expected across Northern California, where a pair of powerful storms began on Sunday night and were forecast to last into the week.

A dispute over the impact of H-1B visas on U.S. workers has been overshadowed by racist rhetoric, with troubling echoes of the great replacement conspiracy theory.