Police found him dead from a self-inflicted gunshot wound.
Police responded to a call around 1:30 a.m.at the Hyatt Regency in Houston, Texas, and attempted to arrest the man for being intoxicated and trespassing.
USA police say they arrested him after the weapons were discovered at the Hyatt Regency in downton Houston in the early hours of Sunday morning. Hotel staff said he was drunk at the bar, and refused to leave. The scene inside the accommodation is reminiscent of the Las Vegas shooter earlier in 2017, who stockpiled weapons and ammunition inside his hotel room.
Senties says investigators don't believe the man intended "to use the weapons or to cause any kind of issue".
He was booked with trespassing and unlawfully carrying a weapon.
The Hyatt has a sprawling New Year's Eve party planned for midnight Sunday, according to its website.
Lt. Gordon Macintosh says other officers arrived to take him into custody and found a rifle, shotgun and handgun in his room, plus ammunition.
Acevedo said on Twitter earlier Sunday that the situation was "contained" and there were no specific threats to Houston. A police spokesman said investigators couldn't speculate about the man's intent with the guns.
Police are still investigating the incident.