Manhattan Mass Shooter's Mom Told 911 He Was Being Treated for Sports-Related Concussions Before Targeting NFL: Cops By Samira Asma-Sadeque

The mass shooter who killed four people in Manhattan last week had suffered multiple sports-related concussions, according to an emergency call from his mother released by Las Vegas police.

Shane Tamura, 27, turned the gun on himself after killing 4 peoplein New York City on July 28. The attack left 4 people dead: NYPD officer Didarul Islam; Wesley Lepatner, an executive at Blackstone; Rudin Management employee Julia Hyman and security guard Aland Etienne.

On Wednesday, Las Vegas Metropolitan Police released a trove of public records related to the department’s previous interactions with Tamura, who lived in the the Nevada city.

The records included a 2022 911 call made by his mother, who said her son was threatening to take his own life. She said Tamura, once a celebrated high school football star, was being treated for mental health struggles and sports-related injuries — namely multiple concussions.

“He’s under doctor’s care for depression, concussion — like sports concussions — chronic migraine and insomnia,” his mother told 911 dispatchers.

Related Stories

Who Were the Victims of the N.Y.C. Shooting? What We Know About the 4 People Killed

N.Y.C. Shooter, Who Played High School Football, Slammed NFL in Suicide Note and Said He Had Brain Disease CTE

Want to keep up with the latest crime coverage? Sign up for PEOPLE’s free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Tamura claimed in a suicide note recovered from his body that he suffered from chronic traumatic encephalopathy (CTE), a neurodegenerative disease caused by repeated blows to the head and often associated with playing football, authorities previous confirmed to PEOPLE. In the note, he mentioned the NFL, which has its headquarters in the building.

Tamura appeared to hold grievances against the NFL owing to his alleged CTE, which often stems from contact sports and can only be definitively diagnosed post-death.

“Terry Long football gave me CTE and it caused me to drink a gallon of antifreeze,” he wrote in the note, referring to the offensive lineman who died by suicide in 2005 by drinking antifreeze and was posthumously diagnosed with CTE. He added: “You can’t go against the NFL, they’ll squash you.”

“Study my brain please,” Tamura wrote in the note.

The mass shooting was the deadliest in the last 25 years in New York, per CNN.