LAS VEGAS (KSNV) — Law enforcement investigated a second property in Las Vegas, likely associated with the gunman who killed four people, including a New York Police Department officer, during a shooting in a Manhattan skyscraper.

Shane Tamura, 27, entered the building located at 345 Park Av., on July 28 carrying an M-4 assault rifle, according to officials in New York.

The building has several companies, including investment firm Blackstone, and the National Football League (NFL) headquarters, which Tamura was targeting, investigators said.

A suicide note was found on Tamura, who shot himself on the 33rd floor of the building in the offices of Rudin Management, according to Mayor Eric Adams. He said the preliminary investigation uncovered that Tamura took the wrong elevator while trying to access the NFL headquarters, as reported by NBC News.

After New York authorities identified Tamura as being from Las Vegas, Las Vegas Metropolitan Police responded to a home in Desert Shores by Lake Mead Blvd and Rampart Blvd.

Authorities also visited an apartment on Tuesday on Paradise Road.

MORE ON NEWS 3 | New York gunman once arrested at Las Vegas casino for trespassing: police report

A source confirmed with News 3 that a second suicide note was found during the course of the investigation in the apartment that mirrors one discovered on his body in New York, which blamed football for his mental health issues.

New York authorities reported that Tamura had a documented mental health history.

A spokesperson for Horseshoe Las Vegas said Tamura worked as a surveillance department employee at the resort.

News 3 first reported on Monday that Tamura was arrested in September 2023 for trespassing. Documents obtained by News 3 revealed it was at Red Rock Casino Resort and Spa.

The paperwork stated Tamura was at the casino cage and refused to leave, leading a security officer to contact LVMPD.

The security officer said Tamura was playing a table game and refused to show ID. He was asked to leave the casino and walked to the cashier. He demanded to collect $5,000, but still refused to show his ID.

According to a police sergeant, Tamura was agitated and reached out toward a security officer in an apparent attempt to grab them. The sergeant "used an empty hand tactic and escorted Shane towards a wall to detain him," the report stated.

Tamura was handcuffed and taken to a security holding cell, where he eventually gave his name and date of birth after being told he could be arrested. The officers then escorted him outside to the parking lot and told him he was trespassing, meaning he was no longer allowed on the property.

"Instead of leaving property, Shane leaned on the patrol vehicle and threw his ID card on the hood," the report states. "Shane was given back his ID and told to leave the property or he will be arrested. Shane still refused to leave and asked how he will get his money."

Officers arrested him for trespassing as a result and booked him into Clark County Detention Center. Tamura was later released on his own recognizance, and court records show the Clark County District Attorney's Office dropped the case two months after his arrest.

Court records also show traffic violations, including in May 2024 for driving without a valid driver’s license and operating an expired, unregistered vehicle.