DAYTON, Ohio — Within seconds, officers patrolling an entertainment district in Dayton, Ohio, killed a gunman who opened fire early Sunday, police said. Nine people, including the gunman’s sister, died in the shooting and 27 others were injured, Dayton Police Chief Richard Biehl said at a news conference Sunday afternoon. He said one of the 27 hurt remained in critical condition.

The shooting in the Oregon District was the second mass shooting in the U.S. in less than 24 hours. Twenty people died and more than two dozen were injured Saturday when another young man opened fire in a crowded El Paso, Texas, shopping area.

The suspect in the Dayton shooting was 24-year-old Connor Betts, police said. His sister, 22-year-old Megan Betts, was the youngest of those killed. She was one of four women who died, along with five men.

Thomas McNichols, 25; Nicholas Cumer, 25; Lois Oglesby, 27; Monica Brickhouse, 29; Logan Turner, 30; Beatrice Warren-Curtis, 36; Saeed Saleh, 38 and Derrick Fudge, 57 were the others killed.

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Biehl said officers patrolling the historic district with bars, restaurants and theaters heard the gunfire, saw people running and immediately responded. Within 30 seconds, six officers who engaged the gunman each fired at least one shot, Biehl said, adding that the shooter fired dozens of bullets before being killed by police.

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At an earlier press conference, Ohio's senators, Democrat Sherrod Brown and Republican Rob Portman, joined Dayton's mayor, police and other officials from the state. The senators called on Senate Majority Leader Mitch McConnell and their peers in Congress to address the numerous mass shootings the nation has been experiencing.

“Are there more things that can be done? I’m sure there are, but I will say there’s something deeper going on here," Portman said.

He said there are not enough laws to address mental health and other issues.

"In fact, no law can correct some of the more fundamental cultural problems we face today as a country, and the shooting last night is an indication of that," Portman said. Both he and Brown said they look forward to trying to reach an effective response to the shootings.

Dayton Ohio Shooting AP
Authorities work the scene of a mass shooting, Sunday, Aug. 4, 2019, in Dayton, Ohio.
AP Photo/John Minchillo

Police said the gunfire began outside shortly after 1:00 a.m. Officials said the shooter was wearing a ballistic vest, a mask and hearing protection while armed with an assault rifle, which used a high-capacity magazine carrying .223 caliber ammunition and extra magazines.

Biehl described the gun as “AR-15-like,” and confirmed it was modified and not sold in Ohio.

The chief said the shooter, his sister and a friend all arrived at the area together in the same car but separated at some point. Law enforcement is still investigating what the shooter did in the meantime and said it’s unclear when or where he went to get the rifle and gear.

What's not known is whether Betts targeted any of the victims, including his sister

While the gunman was white and six of the nine killed were black, police said the quickness of the rampage made any discrimination in the shooting seem unlikely.

Any attempt to suggest a motive so early in the investigation would be irresponsible, the police chief said.

Dayton Ohio Shooting AP
Authorities work the scene of a mass shooting, Sunday, Aug. 4, 2019, in Dayton, Ohio.
(AP Photo/John Minchillo)

Dayton Mayor Nan Whaley said without the quick police response, hundreds more people could have died.

"I just question when is enough, enough?" she said, noting it was the 250th mass shooting in the U.S. this year, with Saturday's in El Paso marking 249.

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Of the 27 injured in Dayton, 15 have been discharged. Four hospitals received victims. 

The FBI said people with video, photos or other evidence from the scene can submit content online at www.fbi.gov/daytonshooting.

A family assistance center was set up at the Dayton Convention Center, and those looking for information can call 937-333-8430. The community blood bank is supporting the hospitals, and while it's closed Sunday, it will reopen on Monday.

Dayton police are handling the investigation, with assistance from the FBI as well as other federal and state resources.

Ohio Gov. Mike DeWine ordered that flags remain at half-staff. He said he’s heartbroken, calling the shooting a “horrible attack.” He also commended the city's police and other first responders for their bravery and quick response.

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President Donald Trump also said on Twitter that he authorized flags at all federal government buildings to fly at half-staff in honor of victims of both the Ohio and Texas shootings.

Trump also tweeted that the FBI, state and local law enforcement are working together/article/news/nation-world/20-dead-26-wounded-in-el-paso-shooting-suspect-in-custody/507-691b5cd1-5201-49c6-8c29-580ae6cd317b in Dayton and El Paso.

Last week, on July 28, a 19-year-old man killed three people, including two children, and injured 13 others at the popular Gilroy Garlic Festival in northern California before law enforcement officers killed him.

The 21-year-old El Paso shooting suspect surrendered to police, and authorities are considering evidence over whether to prosecute him on hate crime charges.

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