ALERT: Manhunt underway in Matoaca after suspects lead police on chase

This is the killer of 26 people: Adam Lanza

The male subject identified as the shooter at Sandy Hook Elementary School has been positively identified as Adam Lanza.

His cause of death was gunshot wound and his death has been ruled a suicide, said police.

As with any murder-suicide, the suspect in the Sandy Hook Elementary School shooting took to his grave the reasons that compelled him to kill more than two dozen people before taking his own life in the second deadliest school shooting in U.S. history.

But those who knew the alleged shooter grasped to reconcile the difference between the quiet, withdrawn 20-year-old without a criminal record — and the man who, dressed in black fatigues and a military vest, rained hell at the Newtown, Connecticut, school last week.