The widower of a former Maricopa County Attorney shot and killed two women before killing himself during a holiday party on Christmas Eve, according to police. David De Nitto, 47 — the former husband of Allister Adel, who died in 2022 a month after resigning as county attorney — was found dead at a home near 5700 North 2nd Avenue about 11:30 p.m. on Sunday, according to the Phoenix Police Department…