According to police, the man ignored commands to drop the weapon and moved the gun toward the officers causing an officer to fire at him, police said.
Las Vegas police said the arrest happened about 1 a.m. Sunday, which began with the man approaching two uniformed officers inside The Venetian casino-hotel.
Police said the man was "acting erratic" and told the officers there were people "chasing him".
Police say it started as a domestic situation with a man was threatening his family with a gun. As the fight escalated, police said, one officer hit the man multiple times with a closed fist, then used a chokehold-like technique called a lateral vascular neck restraint to control him.
The man lost consciousness and died at a Las Vegas hospital trauma center a short time later.
The Associated Press reported that the Office of Internal Oversight and Constitutional Policing are investigating the death.
"Too many people have died as a result of this type of excessive force and too many questions remain about the use of chokeholds by our police". A Venetian spokesman, Ron Reese, referred questions to police. Per deppolicy, the identity of the officer involved will be released after 48 hours, per department policy.
It wasn't immediately clear if the fatal struggle was captured on security video.
Officials say that, as they caught up to him, the suspect attempted to enter a vehicle and they were forced to use a Taser on him.
Speaking to local media last week, Undersheriff Kevin McMahill said: "Our officers are trained to exhaust all of their options before resorting to the use of deadly force".
Eugene O'Donnell, a professor at the John Jay College of Criminal Justice, says police in NY are taught not to go for the neck under any circumstances. "In the midst of a violent interaction, it's different from doing it in a classroom".