Convicted killer Chad Daybell was sentenced to death Saturday for the grisly slayings of his first wife and the two youngest children of his second wife, imprisoned-for-life “Doomsday Mom” Lori Vallow Daybell. Daybell, 55, sat with his hands in his lap and showed no reaction as Judge Steven Boyce announced the jury’s unanimous decision in Boise, Idaho, the Associated Press reported. The punishment came two days after the self-published author of doomsday fiction loosely based on Mormon teachings was convicted of conspiracy, first-degree murder and related crimes in the killings of 49-year-old …