A Missouri mom allegedly gunned down her estranged husband, then drove across state lines to shoot the father of one of her other kids, killing the new girlfriend he was with, according to cops. Taylor Santiago, 31, gave a dead-eyed stare in her mugshot after allegedly turning herself last week for the shocking two-state murder spree, according to the Aurora and Marionville Police Department . The mom randomly “decided” on the killing spree while grabbing coffee at a local general store in Aurora, according to an affidavit obtained by the Kansas City Star , which said she was enraged…..