Authorities don’t know exactly what led a 24-year-old Walmart employee of an Arizona Walmart store to turn on her coworkers, but say that she had a series of potentially deadly plans for them that fell through. What began as a dispute inside the store could have turned tragic when she returned with a rifle, ammunition, a knife, and a torch.

Police recounted to the Arizona Republic that the employee returned to work around 6:30 in the morning after a dispute with coworkers during a late-night shift. She damaged a cash register on her way out, but didn’t hurt anyone.

When she returned to the store, she brought a .22 caliber rifle, a knife, and a torch, but wasn’t able to deploy any of these things. Police say that she didn’t know how to load the rifle, dropped the knife outside in the dark, and was only able to light a tiny pile of trash on fire, which couldn’t sustain itself and went out.

At home, she left a note detailing her plans to kill her coworkers and to force police to kill her. She also texted family members, but it was a customer at the store who spotted the employee on her way in with her (unloaded) rifle, telling a store manager, who in turn called the police.

All the same, she was arrested on suspicion of premeditated attempted homicide, arson of an occupied structure and weapons misconduct.

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