UPDATE: Las Vegas Shooter was "Well Known" by Casinos in the Area. [VIDEO]

As more details have come to light concerning Stephen Paddock, the man accused of opening fire on an outdoor concert in Las Vegas, more questions also surface. Paddock, who killed at least 50 concert-goers, reportedly booked his room at the hotel and had been staying there, under his friend's name, since last Thursday. Paddock was found dead in his hotel room of an apparent self-inflicted gunshot wound but left no clue why he went on the shooting rampage.

The Daily Mirror reports:

"He is believed to have used a high-powered assault rifle to blast his victims. He then killed himself.

The incident took place at the end of a performance by Jason Aldean. Police responded to the shooting at about 10pm local time.

Video clips posted online captured what sounded like automatic weapons as panicked concert-goers fled and dropped to the ground, screaming."

Good Morning America has the latest updates. Watch their coverage below.