Following a July shooting at a Manhattan office tower by a gunman believed to be targeting National Football League headquarters, the league is moving swiftly to beef up security at all team and league facilities across the United States.A memo circulated to all teams on Aug. 8, lays out three major recommended changes to security protocols. These recommendations will face further review at a special league meeting set for Aug. 26.“In moments like these, we are reminded that safety is not a background function. It is foundational,” the memo stated.According to the Associated Press, the proposed upgrades include comprehensive threat assessments at every facility to accurately pinpoint and neutralize risks; the deployment of armed officers whenever players or staff are present; and weapons screening for anyone seeking entry. .UPDATED: NYC shooting suspect blamed NFL, slain NYPD officer's father, wife hospitalized.Screening would involve walk-through magnetometers and X-ray scanners for bags — much like the security measures fans face when entering games.“The Committee recognizes that these changes will affect day-to-day operations and require an investment of time, coordination, and resources,” the memo continued.“However, there is no higher priority than the safety and security of our players, coaches, staff, and everyone who works in and around our facilities.”The shooting occurred July 28, when 27-year-old Shane Tamura of Las Vegas opened fire in the lobby and later on a 33rd-floor office in the building that houses NFL offices — before turning the gun on himself.Investigators say Tamura, who had a history of mental illness, left a note expressing a grievance against the NFL. He claimed to be suffering from chronic traumatic encephalopathy, a degenerative brain disease that can only be diagnosed after death. Tamura played high school football in California roughly a decade ago but never made it to the NFL.