NYPD Says Somebody Else Supplied Part of Tamura's Gun

Investigators plan to question a man who supplied parts for a gun used in Monday's shooting at a Manhattan office building that houses the NFL's headquarters, New York City Police Commissioner Jessica Tisch said Tuesday. Shane Devon Tamura tried to target the NFL headquarters on Monday but took the wrong elevator, Mayor Eric Adams said. The shooter killed four people including a New York City police officer and wounded a fifth before taking his own life, authorities said. "The weapon used, an AR-15-style assault rifle, was assembled by Mr. Tamura using a lower receiver purchased by an associate," Tisch said. "We have located that associate and others. And will be questioning him about that purchase."

The commissioner said the associate will be questioned as part of a larger effort to trace the gunman's movements from Las Vegas to New York City, the AP reports. "This information will give us a detailed picture of how and why this happened," Tisch said, "but it will not do anything to ease the pain of losing one of our own."

• Tisch said that two groups of detectives are on their way to Las Vegas to conduct interviews and execute a search at Tamura's home. The officers will also visit the gun store where he legally purchased a revolver on June 12 using a Nevada concealed carry permit, she said. Meanwhile, police in Manhattan are executing search warrants on the gunman's car and the two phones that he left at the scene.
• Tamura was scheduled to appear at his overnight security job at the Horseshoe Las Vegas on Sunday, but he never arrived to work, Tisch said. Caesars Entertainment confirmed Tuesday that Tamura worked in the casino's surveillance department.
• Police said Tamura had a history of mental illness, and a rambling note found on his body suggested he had a grievance against the NFL over an unsubstantiated claim that he suffered from chronic traumatic encephalopathy. The 27-year-old had played football in high school in California but not in the NFL.
• Law enforcement sources tell ABC News that Tamura was placed under mental health crisis holds in Nevada in 2022 and 2024. According to a police report, he was arrested in September 2023 on suspicion of trespassing at the Red Rock Casino Resort & Spa in Las Vegas, but the charge was later dropped.