MIDTOWN, Manhattan, New York A devastating mass shooting at a Manhattan office building has left four individuals dead and one injured, including an off-duty NYPD officer. The incident, which unfolded on Monday, has been described by New York City Mayor Eric Adams as an 'intentional, sick, twisted act of violence,' with security camera footage revealing the gunman's methodical and chilling approach. The victims include Wesley LePatner, a Blackstone employee; NYPD Officer Didarul Islam, who was working a private security detail; security officer Aland Etienne; and Rudin Management employee Julia Hyman. An NFL employee was also wounded in the attack. Deputy Mayor Kaz Daughtry recounted harrowing details, including the heroic actions of the injured NFL employee who warned colleagues upstairs, and a maid who narrowly escaped the gunman's pursuit. Surveillance video captured the gunman, 27-year-old Shane Tamura, opening fire immediately upon exiting an elevator on the 33rd floor, shattering glass doors. Tamura was later found dead from a suspected self-inflicted gunshot wound. Investigations into Tamura's motive revealed suicide notes found in his Las Vegas studio apartment, blaming the NFL for a traumatic brain injury and mentioning CTE. Law enforcement sources also discovered a rifle tripod and ammunition. Disturbingly, Tamura acquired the rifle and the BMW used in the attack from his supervisor at a Las Vegas casino, who stated he legally purchased the weapon before selling it, though unaware of Tamuras intentions. The killing of Officer Didarul Islam, the first NYPD officer of Bangladeshi descent killed in the line of duty, has deeply impacted the community. Funeral services were held for Islam, a father of two with a third child due soon, drawing attendance from Governor Hochul, Police Commissioner Tisch, and Mayor Adams. Governor Hochul, reflecting on the tragedy, has called for stricter federal gun control measures, criticizing the availability of semi-automatic rifles and emphasizing the need for 'legislation, not vigils.' Mayor Adams commended the rapid and courageous response of NYPD officers who entered the building, knowing a shooter was present, without hesitation. Tamura's former football coach from Southern California expressed disbelief, noting Tamura's past ankle injury but no known head trauma. Teammates described Tamura as a 'goofball' and a 'great guy' who was not problematic, adding to the shock surrounding his actions. Police found notes in Tamuras pocket directly accusing the NFL of concealing dangers to players' brains and asking for his brain to be studied for CTE. While Tamura had no known connection to the NFL and CTE cannot be definitively diagnosed in living persons, his brain will be examined post-mortem. It was also revealed that Tamura had a documented mental health history and possessed a concealed firearms permit from Las Vegas. The FBI is actively investigating the motive behind this heinous act.