LOUISVILLE, Ky. (AP) — The man who fatally shot five coworkers at a Louisville bank in April wrote in his journal that he wasn’t sure if his mental health struggles would preclude him from purchasing a gun and then later, after acquiring one just days before carrying out the mass shooting, remarked on how easy the transaction turned out to be.

The journal writings by Connor Sturgeon were contained in a 64-page report released Tuesday by Louisville police, where authorities say they have now closed the investigation into the actions of the 25-year-old who also died that day in an exchange of gunfire with authorities.

Sturgeon wrote that it “was so easy” to purchase the assault rifle, a Radical Firearms RF-15, from a Louisville gun store, according to the police file. He bought the rifle, 120 rounds and four magazine cartridges for $700 six days before the shooting, and the process took about 45 minutes, he said.

“Seriously, I knew it would be doable but this is ridiculous,” he wrote.

He also acknowledged his struggles with mental illness and said he was dissatisfied with his job and the direction his life was taking. He wrote that he was “very sick” and suggested that he had lied about his health to avoid further treatment or institutionalization.

The April 10 shootings began when Sturgeon opened fire in a conference room in the downtown high-rise bank building. One of the first officers to respond was struck in the head and critically wounded. Another officer shot and killed the gunman in the lobby.

Sturgeon fired more than 40 rounds over the course of about eight minutes, according to the report. Investigators remarked that it appeared he “did not have a firm understanding” of how to operate the weapon.

The report noted that investigators did not find “evidence of long-term planning,” though there were references in his journals to what he intended to do in the days beforehand. Nor did investigators find evidence he made extensive online searches related to gun violence.

Sturgeon’s family has said they intend to sue the maker of the rifle used in the attack. His parents said his mental health struggle began a year earlier with panic attacks, anxiety and a suicide attempt, but he was seeing a psychiatrist and taking medication.

His mother, Lisa Sturgeon, said his roommate called her the morning of the shooting to say Sturgeon told him by phone: “I’m going to go in and shoot up Old National.” She called 911, but her son was already at the bank.

The five employees killed were Joshua Barrick, 40, a senior vice president; Deana Eckert, 57, an executive administrative officer; Tommy Elliott, 63, also a senior vice president; Juliana Farmer, 45, a loan analyst; and Jim Tutt Jr., 64, a commercial real estate market executive. Elliott was a close personal friend of Kentucky Gov. Andy Beshear.

Eight others were injured including Nickolas Wilt, the officer who was shot in the head and who was released from the hospital in late July after months of rehab.

Sturgeon was shot by an officer in the right arm twice, the left leg once and once in the head, according to the report.

Investigators determined that the actions of the officer who shot Sturgeon were not criminal, the report said.