Mass Murders Captivated Online User Believed To Be Adam Lanza

Adam Lanza lived in this home with his mother, Nancy Lanza. (STEPHEN DUNN)

In all, Lanza fired 154 shots, killings 20 first-graders and six women. Lanza fatally shot himself with a handgun as police were entering the building.

The suspected interest of Lanza in the Wikipedia massacre articles is consistent with evidence police found inside the Lanza home.

During a search of Lanza's room and other parts of the house, police found a New York Times article about the mass murder at Northern Illinois University in 2008, in which five people were killed and 21 injured when a gunman opened fire in a lecture hall.

Law enforcement sources have told The Courant that police also found news articles in the Lanza home about Norway mass murderer Anders Breivik, who killed 77 people in 2011.

What investigators believe to be Lanza's online persona exposes a different dimension from what evidence suggests was an isolated lifestyle from age 17 on. The poster seems engaged with others online and is often helpful when comfortable with the topic, such as suggesting a particular firearm for someone in the chat room who said he was 18 and looking for a rifle as a gift. The poster recommends a semiautomatic rifle that "can be found for under $650."

In the virtual world, the poster appears to have some stature. On the gun websites, the poster believed to be Lanza operates as an equal with others on the website who appear to be older, seasoned firearms experts.

The poster also was not shy about starting a debate online, asking in chat rooms on glocktalk.com in April 2009 whether adding RAM to a computer increases its speed.

"Am I just an inattentive philistine or has additional RAM in a computer which was not already deprived of it never helped any of you?" the poster asks.

The poster appears to be part of a video gaming "clan," communicating with the others through myshoutbox.com in February 2010. At one point, some fellow gamers appear to be lamenting the departure of the poster, and of others, from the clan.

"I know," said one person in March 2010, referring to the poster believed to be Lanza and two others. They "set the clan apart from all other clans."

Another poster said, "Same. It's just not the same without them."

The posts suspected to be Lanza's stop abruptly in late February 2010.