Go inside the investigation into one of the worst school shooting massacres in U.S. history.
No clear motive was spelled out in the 44-page summary of the investigation into last year's massacre at Sandy Hook Elementary School that was released Monday. However, new photographs of the scene -- and shooter Adam Lanza's home -- were released. Here is a sampling:
Mario Tama/ Getty
National Archives and Records Administration
Mark Davis/Getty Images
iStock / Spauln
Cindy Ord/Getty Images for Autism Speaks
WDBJ via Newsource
Barry Williams/Getty Images
Walt Disney Productions
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