Right Now: The authorities said that they have killed the gunman, identified as Stephen Paddock, 64.
• The death toll has surpassed 50, with more than 200 injured, in a shooting at an outdoor concert near the Mandalay Bay Resort and Casino in Las Vegas, the police said.
• Sheriff Joseph Lombardo said the exact number of injuries had yet to be determined. “Obviously this is a tragic incident and one that we have never experienced in this valley,” he said.
• The police said they had killed Mr. Paddock, who was believed to be the only attacker.
• Automatic gunfire can be heard in videos from the grounds of the concert, a country music event known as the Route 91 Harvest Festival. Concertgoers were seen running and ducking for cover. Thousands of people fled.
The police say the gunman is dead.
The sheriff said the gunman’s background was largely a mystery and his motive was unknown. He predicted “a long and tedious investigation.”
“As far as his history and background, we haven’t completed that part of the investigation yet,” he said. “But we located numerous firearms within the room that he occupied.”
At least two police officers have died.
Two off-duty Las Vegas police officers were killed in the shooting, Sheriff Lombardo said at a news conference.
Two other officers responding to the scene were wounded, the sheriff said. One of them is in critical condition.
Additionally, an off-duty officer from Bakersfield, Calif., who was attending the concert was taken to the hospital with injuries that were not believed to be life-threatening.
The sheriff described the gunman as a “local resident.”
Police hunt for gunman’s ‘companion.’
The police said they were “confident but not 100 percent sure” that they had located Marilou Danley, a woman they described as “a companion that is traveling with” Mr. Paddock.
The authorities have called her a “person of interest” and the shooter’s “roommate.” The police also said they had located two cars whose license plates were registered to Mr. Paddock.