In the weeks after Minnesota's worst workplace shooting in recent history, investigators scoured Andrew Engeldinger's laptop, digital camera and telephone for any clues to explain why he killed six people before shooting himself in the head.

They came up empty.

Forensic experts from the Minneapolis Police Department examined 38,942 images and more than 200 videos and noted that none of them was of "immediate, recognizable, relevance," according to crime scene and personnel documents obtained by the Star Tribune on Monday. What they did find was 6,373 hits on the word "Glock," and files created in October 2011 related to buying the gun and applying for a federal firearms license.

Engeldinger, 36, shot his victims with a Glock 9-mm semi-automatic pistol at Accent Signage Systems in Minneapolis after he was fired from his job. A manila envelope marked "Andy" with his final paycheck of $968.46 was found on the office floor of Director of Operations John Souter, one of a pair of employees who were shot and survived.

There was a letter in Engeldinger's personnel file dated the week before the shootings from his supervisor, Rami Cooks, warning him about his chronic tardiness and saying that "we need to rectify this issue immediately."

"We have discussed your chronic late arrivals several times in person, but the message does not seem to be getting through," Cooks wrote.

A gruesome scene

The 20-page forensic report detailed what officers saw when they reached Accent in the late afternoon of September 27. In addition to Minneapolis SWAT teams, a slew of Brooklyn Park police officers gathered outside the building in case a "secondary mission" was necessary. An armored vehicle also was brought to the scene, as well as a bomb squad to handle a gray backpack found inside a loading door and to search Engel- dinger's car.

Inside, police discovered Engeldinger had killed company founder and owner Reuven Rahamim, Accent employees Eric Rivers, Ronald Edberg, Cooks and Jacob Beneke and UPS driver Keith Basinski.

Accent employee Battites Wesley was the only other surviving shooting victim.

Engeldinger's body was found in a chair in the basement, the Glock at his feet. Two live cartridges were in the gun. A bullet was retrieved from his left hand and arm.

He fired at least 46 bullets. Officers said many of the victims had large pools of blood around their heads. One victim had a gray plastic bag with unknown items under his left arm.

When police searched Engeldinger's computer, they uncovered nothing significant in his e-mails, instant messaging, chat history, Web browsers, peer-to-peer sharing programs or cloud-based applications. His telephone showed five incoming calls hours after he died.

He was told he was fired in a meeting with Souter and Cooks after he worked his shift. He then went to his car and got a gun. He bought two Glocks a year before the shootings.

Engeldinger started with Accent in 1999 as a hot stamper. On his application, he said he was intelligent, detail oriented and reliable. He made approximately $20 an hour and was consistently approved for raises. In 2007, he transferred $27,000 to different funds for his 401K and profit-sharing plan.

At least nine letters related to workplace performance were placed in Engeldinger's personnel file since 2000. After his first three months on the job, Cooks wrote he was pleased with his work, but that he could improve on time management.

In October 2006, Souter raised concerns about Engeldinger's lack of production after a car accident. At that time, he was the lead person in the engraving area.

A month later, he complained to Rahamim that "everyone is abusive to me" and he needed to talk to an attorney.

In 2007, Souter recommended Engeldinger take a leadership role in training new personnel, but in a "respectful manner."

"We will give him a 60 day trial to see if Andy can step up to the plate," he wrote.

Several people complained that Engeldinger made disparaging remarks and that his behavior may have caused several people to leave the company. He was removed from the leadership role and Souter told him "that under no circumstances would Accent tolerate continued disrespectful behavior from anyone."

Last July, Engeldinger received a letter for being late to work 15 out of 16 work days. Further incidents could lead to termination, the letter said.

Earlier this year, Souter placed one final letter in his personnel file in regard to sloppy work. Engeldinger was disrespectful in his conversation with Cooks over the matter and Souter had to intervene.

"I informed Andy that if there is a problem with communications, my door is always open and I would listen to both sides of the review," Souter said.

Engeldinger's family hadn't had contact with him for about 21 months before the shooting and were worried about his paranoia and delusions.

David Chanen • 612-673-4465