Officers eventually found Engeldinger dead, seated in a chair in the basement with what appeared to be a self-inflicted gunshot wound, according to the police reports. His Glock 9 mm semi-automatic pistol was near his feet.
Souter told police at the hospital that night that Engeldinger was an introvert. According to documents in his personnel file, his shortcomings on the job included the quality of his work, showing up late and problems in his dealings with other employees.
Another report detailed police interviews with Engeldinger's parents, who have said their son struggled with mental illness for years and had shut them out of his life for nearly two years before the attack. Engeldinger's mother told police her family had a clinically diagnosed history of schizophrenia, and described her son as "competitive and intelligent."
His father said Engeldinger was "competitive and liked things done by the book." He said his son was made fun of as a teenager for having "a high level of intelligence," and also said his son went through a drug rehab program in his late teens or early 20s.
Both parents said their son didn't have a girlfriend and had "no known friends."
One report said the gun used in the attack was purchased in October 2011 from KGS Guns and Ammo in Minneapolis. The shop's owner, Mark Koscielski, told The Associated Press that he sold Engeldinger the gun — he recalled the price as around $620 — after Engeldinger filled out a permit-to-purchase application with police and passed an FBI check. He said he made small talk with Engeldinger because he noticed his address wasn't far from where Koscielski grew up, but nothing stood out in memory about the conversation.
After that, Koscielski said, "He just came in a few times to window-shop, but that's about it."
Associated Press writers Doug Glass and Patrick Condon contributed to this report.