Michigan authorities suggested that the shooter who attacked eight students at Michigan State University and killed three was found to have possessed two handguns and a note that could indicate his motive in the horrific assault.

Officials found 9 mm guns, dozens of rounds of ammunition, and a two-page note with the suspect's body, identified as Anthony McRae after he killed himself on Monday. The shooter's suicide happened after police officers confronted him, said campus deputy chief Chris Rozman.

Michigan State Shooting Motive

Currently, investigators are still trying to determine a motive for the crime, but they said that the note found in McRae's possession is a crucial point. During a news conference, Rozman said that the note's content appeared to have suggested that the shooter felt he was slighted in some way by people or businesses.

He questioned whether or not a mental health issue could have amplified McRae's attack. He noted that authorities are still unsure of the exact reasons that the killer had but noted that they would determine it as best as possible in the coming days or weeks, as per the Associated Press.

The 43-year-old shooter was believed to be alone when he conducted the attack, and he was found to have no connections to any of the victims or Michigan State as a student or employee, said police.

The campus deputy chief described the ongoing investigation as "massively complex." The killings occurred on Monday during evening classes at Berkey Hall and nearby at the MSU Union. The latter is a social hub where students usually study, eat, and relax.

Authorities told students from the campus to shelter in place for hours when the incident began, telling them to run or fight if necessary as police searched for the gunman. Some of the residence halls were located roughly a mile away from the scene of the shootings.

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Students Fleeing For Their Lives

According to CBS News, the note officials found in McRae's possession also included him threatening several institutions, such as a church, a New Jersey school district, and various businesses to which he had personal ties.

Michigan State Police Lt. Rene Gonzalez on Thursday said that the note on McRae would help determine the attacker's motive. The official added that the investigation discovered that the shooter had contact with some of the places listed in the two-page document.

McRae was reportedly an employee of the Meyer warehouse at one point in time, as well as a couple of other businesses. Gonzalez noted that the suspect appeared to have quarrels with the businesses' employees when he was asked to leave.

Students at the shooting scene were forced to jump out of windows and run for their lives as McRae went on a rampage. That scene was similar to many other mass shootings in the United States. On Tuesday, one sophomore, Claire Papoulias, said that she was in history class when she suddenly heard gunshots directly behind her, said CNN.

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