The Nevada man who shot and killed four New Yorkers, including an off-duty NYPD officer, may have been targeting the National Football League, which is headquartered in the midtown Manhattan building the shooter attacked, city officials said. Shane Tamura, 27, played football for Golden Valley High School in Santa Clarita and Granada Hills Charter School on Zelzah Avenue in Granada Hills.

Tamura, drove from his home state of Nevada to New York City where he exited a double-parked BMW and brandished an automatic rifle as he walked into the office building at 345 Park Avenue. In the lobby he immediately shot and killed 36-year-old NYPD officer Didarul Islam, who was working uniformed security detail, and a woman who took cover behind a pillar, law enforcement said. He then boarded the elevator to the 33rd floor, to a real estate management company, where he continued shooting and ultimately turned the gun on himself.

Before his death, Tamura killed four people and shot one other, who is in the hospital in critical condition.

Tamura played running back for the Golden Valley High School football team as a player in the 2014–15 season.

A video of his football highlights at Golden Valley High School can be found at www.hudl.com/profile/2954389/Shane-Tamura.

He transferred to Granada Hills Charter School, where he played varsity football and graduated in 2016. Tamura did not play football in the NFL, according to reports.

According to MaxPreps.com records, Tamara played for Granada Hills in the 2015 season and he rushed for 616 yards on 126 carries, averaging 4.9 yards per carry and scoring five rushing touchdowns with a total of eight touchdowns.

Police found a note in Tamura’s pocket claiming he suffered from chronic traumatic encephalopathy, a brain injury caused by repeated head trauma, which has been studied for its prevalence among professional football players. CTE cannot be diagnosed until a person is deceased.

“Study my brain please. I’m sorry,” wrote Tamura, who played high school football in Los Angeles and had a documented mental health history, according to law enforcement.

The note also accuses the NFL of concealing the dangers of CTE to maximize its profits, according to news reports.

“He seemed to have blamed the NFL,” New York City Mayor Eric Adams said Tuesday told WPIX-TV on Tuesday morning. “The NFL headquarters was located in the building, and he mistakenly went up the wrong elevator bank.”

The NFL reported that one of its employees was seriously injured in the attack and was in stable condition.

“We believe that all of our employees are otherwise safe and accounted for,” the league said in a statement. “We are deeply grateful to the law enforcement officers who responded to this threat quickly and decisively and to officer Islam, who gave his life to protect others.”

The NFL will increase security at the building in the “days and weeks to come,” it said.

The slain officer, Islam, is an immigrant from Bangladesh and a father of two young sons. His wife is pregnant with the couple’s third child. He had been on the force for 3 1/2 years, and was working a paid detail assignment — a program where companies can hire NYPD officers in uniform to provide security.

“He died as he lived: a hero,” NYPD Commissioner Jessica Tisch said at a news conference Monday night.

Tamura used a Palmetto State Armory AR-15 in the shooting, which took place around 6:30 p.m. on Monday. Officers found a rifle case, a revolver, magazines and ammunition in his car, Tisch said.