Deadly Skyscraper Shooting: Gunman Assembled Weapon Himself

On Monday, a deadly attack unfolded in a New York City skyscraper, leaving four people dead. The suspect, 27-year-old Shane Tamura, had traveled from his home in Las Vegas, Nevada to carry out the shooting.

Authorities have revealed that Tamura had assembled the AR-15-style assault rifle he used in the attack himself, from parts. He also had a permit to carry a concealed gun and had used that permit to purchase another firearm, a revolver, just last month.

As investigators work to uncover Tamura's motive, questions are being raised about his history of mental health problems and his recent employment as a security guard at a Las Vegas casino. Tamura did not show up for his usual shift on the day of the attack, instead driving across the country to target the offices of the National Football League, which he accused of hiding the dangers of brain injuries.

The tragic incident has left the community shaken and authorities determined to trace the sources of Tamura's weapons and understand what led him to commit this horrific act of violence.