A Pathmark grocery store (Creative Commons)

Details from the Twitter account of Terence Tyler, the 23-year-old former Marine who shot and killed two co-workers at the Pathmark grocery store in New Jersey on Friday morning before killing himself, show he was having thoughts about killing his co-workers back in 2009.

According to New Jersey.com:

• Using the online handle "Tylerbkstyle," Tyler posted more than 2,000 tweets in 2009, when he was enlisted in the Marines and serving out his contract in California.
• In many of his posts, he talked about his dislike of the Marines, his unhappiness in California and his longing to return to New York City. Tyler commonly used abbreviations and slang, along with numerous profanities, on his page.
• "...is it normal to want to kill ALL of ur coworkers? Maybe but I'm actually in a position where I can," he tweeted on June 1, 2009, adding the acronym "smh," which means "shaking my head" in Internet jargon.
• Three days later, he said, "Grrrr I hope these plp enjoy being annoying cuz whn we deploy they'll all die anyway."

Tyler was discharged from the Marines in Feb. 2010 after enlisting in 2008.

The shooting comes one week after the Empire State Building shooting which also targeted a co-worker.

Reach Executive Producer Paige Brettingen here.