Investigators believe Shane Tamura was trying to get to the NFL headquarters but accidentally entered the wrong elevator, the city’s mayor says.<\/p>\n
Officials said he intended to target the NFL headquarters but took the wrong elevator \u2014 instead spraying the lobby of a skyscraper and killing four people: a police officer, a security guard and two people who worked at companies in the building.<\/p>\n
Police said Tamura had a history of mental illness, and the note found on his body suggested he had a grievance against the NFL over an unsubstantiated claim that he suffered from CTE.<\/p>\n
What did his note say?<\/p>\n
In the three-page note found on his body, the gunman accused the NFL of concealing the dangers of brain injuries linked to contact sports for profits.<\/p>\n
If you or anyone you know needs help:Suicide Call Back Service<\/a> on 1300 659 467Lifeline<\/a> on 13 11 14Aboriginal & Torres Strait Islander crisis support line 13YARN<\/a>\u00a0on 13 92 76Kids Helpline<\/a> on 1800 551 800Beyond Blue<\/a> on 1300 224 636Headspace<\/a> on 1800 650 890ReachOut<\/a> at au.reachout.com<\/a>MensLine Australia<\/a> on 1300 789 978QLife 1800 184 527<\/a><\/p>\n In the note, Tamura “claimed to be suffering from CTE, possibly from playing high school football”, New York Police Commissioner Tisch said.<\/p>\n “Study my brain. I’m sorry,” Tamura was quoted as having written.<\/p>\n The note mentioned a 2013 Frontline documentary featuring former NFL players who suffered from CTE, which has no known treatment and can be caused by repeated shaking of the brain associated with playing contact sports.<\/p>\n What is CTE?<\/p>\n Chronic traumatic encephalopathy can affect regions of the brain involved with regulating behaviour and emotions.<\/p>\n This can lead to memory loss, depression, violent mood swings and other cognitive and behavioural issues, though researchers note that these symptoms can also be linked to other illnesses.<\/p>\n Experts say symptoms can arise years or decades after the last brain trauma.<\/p>\n Evidence of the disease has been found not just in those with long professional careers but in high school athletes as well.<\/p>\n NFL football player Aaron Hernandez’s brain projected on a screen at Boston University’s centre for research into CTE. (AP: Steven Senne)<\/p>\n So, did the gunman have CTE?<\/p>\n We don’t know.<\/p>\n CTE can be diagnosed only by examining a brain after death, and it is unclear whether he was showing symptoms.<\/p>\n Tamura was never an NFL player but he did play high school football in California a decade ago and had a history of mental illness, police said without giving details.<\/p>\n The degenerative brain disease has been linked to concussions and other repeated head trauma common in contact sports such as football.<\/p>\n According to Boston University’s Chronic Traumatic Encephalopathy Center, progressive degeneration of brain tissue in people with CTE includes the build-up of an abnormal protein called tau in a pattern that distinguishes it from other diseases, such as Alzheimer’s.<\/p>\n Why is CTE associated with the NFL?<\/p>\n Researchers have established a connection between CTE and contact sports, military combat and other activities with repeated blows to the head.<\/p>\n<\/p>\n