Timeline of Conn. school shooting - PHOTOS

A gunman killed at least 20 students at Sandy Hook Elementary School in Newtown on Friday morning. Police said the shootings took place in two rooms at the school. At least three weapons were recovered at the scene, including an assault rifle and two semiautomatic handguns. Here is a timeline of what is known. Images courtesy of USA TODAY research, By Anne R. Carey, Joan Murphy, Tory Hargro, Jerry Mosemak, and Janet Loehrke, USA TODAY.