"48 Hours" has disturbing new information about the relationship between a murdered California police officer and his ex-wife. Officer Daniel Green was shot to death inside his home in 2015. At first, Erika Sandoval denied being involved in the murder, but then she changed her story. In his first network TV interview, Green's twin brother tells "48 Hours" correspondent Erin Moriarty that Sandoval seemed capable of violence. Watch the full "48 Hours" report on Saturday, Dec. 7 at 10/9c.