Unanswered questions remain about a fatal shooting at a Madison, Wisconsin, private school Monday as new details emerge about the upbringing of the teenage girl who allegedly opened fire. Investigators are working to piece together how and why 15-year-old freshman Natalie Rupnow,

The shooter has been identified as 15-year-old Natalie Rupnow, who went by the name "Samantha." The teen is alleged to have opened fire with a handgun in a study hall at the school, killing a staffer and student and injuring six others before turning her weapon on herself.