New York shooting: New details emerge about Shane Tamura's actions before attack

The Manhattan mass shooter's chilling final movements and actions have been laid bare.

Shane Tamura travelled more than 2,500 miles from Las Vegas to New York to carry out the horror on Monday night, which saw him kill at least four innocent people. The 27-year-old man then turned the weapon on himself in the skyscraper in Manhattan.

Police Commissioner Jessica Tisch told reporters at a press conference last night Tamura left Las Vegas on 26 July and drove across several states to arrive in New York City on Monday. His vehicle, registered under his name in Nevada, was discovered at the crime scene with a rifle case, a revolver, ammunition, magazines, a backpack and medications prescribed to him, she said.

Numerous calls were made to the New York Police Department by around 6.28pm on Monday, each relating to Tamura wielding a rifle as he stormed the towering office block - home to large companies including KPM, National Football League (NFL) and Blackstone.

The gunman had exited his black BMW, which was double-parked on Park Avenue, and calmy strolled towards the building. His motive was then - and still is now - unclear.

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Tamura entered the lobby of the building, turned right and immediately opening fire on an NYPD officer, Ms Tisch said. He then shot a woman who was hiding behind a pillar, reports the Mirror US.

The Las Vegas native stormed through the lobby, unleashing a hail of bullets, Ms Tisch recounted. He advanced towards the lift area, where he shot a security guard hiding behind a desk. Another individual was injured in the lobby, Ms Tisch noted, mentioning she had received his statement from the hospital.

Upon summoning the lift, which arrived with a woman inside, Tamura let her pass by unscathed before heading up to the 33rd floor, home to Blackstone's offices.

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Reaching the floor, Tamura moved along a corridor, discharging his firearm and fatally wounding one person. "He then proceeds down a hallway and shoots himself in the chest," Ms Tisch disclosed.

A bomb disposal team examined Tamura's car on Park Avenue and declared it free of explosives, she added. Preliminary investigations indicate that Tamura drove through Colorado on July 26, then through Nebraska and Idaho on July 27, according to Ms Tisch. His vehicle reached Columbia, New Jersey on Monday afternoon, before arriving in New York City shortly thereafter.

The reasons behind Tamura's violent spree remain a mystery, but he was known to have a "documented mental health history," Ms Tisch stated.

"We are working to understand why he targeted this particular location."