A trove of 131 online-forum postings written between April and June 2010, which were viewed by The Wall Street Journal, provides insight into Mr. Loughner’s mind-set in the year leading up to Saturday’s shootings in Tucson, Ariz. He stands accused of killing six people, gravely wounding Rep. Gabrielle Giffords (D., Ariz.) and injuring 13 others.

The online postings paint a picture of a disturbed young man trying to impress his peers and struggling to find a purpose to his life. They range from prosaic chatter about weight lifting to nonsensical philosophical ramblings that left some of the gamers who read them wondering whether he was using drugs or had a mental disability…

The online-forum messages exhibit a growing frustration that, at 22 years of age, Mr. Loughner couldn’t land a minimum-wage job and was spurned by women. By May 15, he wrote, he hadn’t had a paycheck in six months. A month later, he wrote that he had submitted 65 applications, yet “no interview.”