Note left by Manhattan office gunman asked for his brain to be studied

Incident Overview - A 27-year-old gunman, an employee at the Horseshoe Casino in Las Vegas, drove from Las Vegas to New York City and opened fire at 345 Park Avenue [1] - The gunman fired more than 50 times in the lobby and on the 33rd floor [1] - The gunman shot himself after killing four people and seriously injuring another [1] Victims - Among the dead were an NYPD officer, a Blackstone executive (Wesley Leatner), and a security guard [1][2] - One man, 41 years old, was in critical but stable condition [1] - Blackstone confirmed the death of their executive, Wesley Leatner, expressing deep sorrow [1][2] Gunman's Motive - Investigators found a three-page note in the gunman's wallet expressing anger and alleging a link between his mental illness and playing football in high school [1] - The gunman requested his brain be studied for CTE (Chronic Traumatic Encephalopathy) due to head trauma from playing football [1] - Investigators believe the gunman chose the location because the NFL is headquartered in the building [1] Investigation - The NYPD retraced the gunman's movements before the shooting [1] - The gunman's computer password was included in the note, suggesting he wanted investigators to delve into his past [1] - Police believe the gunman acted alone [1]