A former footballer suspected of killing four people in a shooting at NFL headquarters may have revealed his motive in a note found at the scene.
On Monday, police believe that Shane Devon Tamura drove across the country from Nevada to New York to commit a terrible crime.
Tamura is suspected of walking into a building in Manhattan that is an office for several businesses, including the NFL, with an M4 rifle and opening fire, killing four people.
New York Police Commissioner Jessica Tisch stated that the 27-year-old initially opened fire in the lobby before travelling up to the 33rd floor and firing again and eventually killing himself.
Police are still working to determine an exact motive for the horrific attack, but a new report has revealed that the suspect may have left a note at the scene that could explain his reasoning.
Four were killed in the shooting in New York. (Image: Getty) Speaking at a press conference after the attack, Tisch confirmed that the suspect appeared to struggle with his mental health, but they are still unsure exactly what led to him committing the shocking attack.
She said: "According to our law enforcement partners in Las Vegas, Mr. Tamura has a documented mental health history.
“His motives are still under investigation.”
However, a report from NBC News claims that officials familiar with the incident confirmed that a note was found at the scene in which the suspect wonders if chronic traumatic encephalopathy (CTE) suffered when he played football could have caused his mental illness.
Another report from ABC News claims that Tamura played as a competitive football player during his time at the Santa Clarita High School in the Los Angeles area.
Throughout his time at school, Tamura played as a running back with Grenada Hills Charter.
Caleb Clarke, his former classmate, described him as a "goofball" when speaking to ABC News and claimed that he did not rememver him having any mental health issues.
Therefore, investigators are currently looking into this as a potential reason why he targeted the Park Avenue building that houses the NFL offices.
Police rushed to the scene of the crime at 345 Park Avenue in Manhattan. (Image: Getty) Alongside the note, Tamura's weapon and ammo and a mobile phone have also been taken for evidence, with officials hoping that phone could provide further insight into what caused the attack.
After the attack, NFL Commissioner Roger Goodell told employees that one member of staff had been injured in what he called 'an unspeakable act of violence' at the office building.
"One of our employees was seriously injured in this attack. He is currently in the hospital and in stable condition. NFL staff are at the hospital and we are supporting his family," Goodell said.
NYPD Officer Didarul Islam, 36, was one of the four people killed in the attack, while the other three victims yet to be identified.