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:
Screen Gems Television
Library of Congress
Patrick Aventurier/Getty Images
Maddie Meyer/Getty Images
Sebastião Salgado via Wikimedia Commons
U.S. Marine Corps
CDC Public Health Image Library
Theo Wargo/Getty Images for Tony Awards Productions
iStock / DrGrounds
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