The gunman who opened fire at a Manhattan office building Monday, killing four people before taking his own life, legally purchased the rifle used in the attack, according to an attorney for the Las Vegas casino supervisor he bought it from.

In an exclusive report, a recent search of Shane Tamura's Las Vegas studio apartment, located just blocks from the Strip, has unveiled critical evidence linked to the tragic New York City shooting. SWAT teams were filmed by Channel 13 as they discovered a suicide note,