9 dead, 27 injured in Dayton shooting; suspect's sister among victims The Ohio mass shooting took place hours after another mass shooting in Texas.

Investigators are working through evidence as they grapple with the aftermath of the deadly shooting in downtown Dayton, Ohio, and what it means to have citizens armed with powerful weaponry.

"It's fundamentally problematic to have that level of weaponry in a civilian environment, unregulated, is problematic," Dayton police chief Richard Biehl said at a Monday morning news conference, a little over a day after a gunman killed nine people and injured dozens before being killed by responding officers.

Biehl said that the suspect's gun "was modified in essence to function as a rifle."

That information came as Dayton authorities deal with the aftermath of the shooting, which took place just after 1:00 a.m. on Sunday morning in a popular part of town that had a number of bars and restaurants.

Biehl said that evidence is still being collected, but if all of the shooter's magazines were full at the time of the shooting, the suspect would have had "a maximum of 250 rounds in his possession at the time" of the shooting. He added that investigators have found "at least 41 spent shell casings" that were used by the shooter, but cautioned that there may have been more.

The suspected shooter, identified by police as 24-year-old Connor Stephen Betts, allegedly carried out the massacre with a .223-caliber rifle that he legally purchased, Biehl said at a news conference Sunday afternoon.

Biehl said the suspect was wearing a ballistic vest, a mask and protective ear muffs when he unleashed a barrage of shots on a street in Dayton's Oregon District, sending hundreds of people who had been out for a fun night on the town running for cover and leaving the sidewalks covered in blood.

The chief said Dayton police officers were patrolling the bustling area of bars and restaurants when they heard the first shots erupt. The first call about the shooting came in at 1:07 a.m., Jeffrey Payne, the director and chief Dayton Fire, said at Monday's news conference.

On Sunday, officials said that 30 seconds after the gunman fired the first shots, he was killed by an officer in front of the Ned Peppers bar.

Biehl said the suspect was attempting to get into Ned Peppers when he was gunned down.

"Had this individual made it through the doorway of Ned Peppers, there would have been catastrophic injury and loss of life," Biehl said.

He added on Monday that they are "not close enough at all" to identify a motive, but race does not appear to be a possible factor.

"We have a lot of evidence still to go through. Just based on where we're at now, we are not seeing any indication of race being a motive, but we are not through all the evidence. And so until we're through all the evidence we cannot rule that out. But I'm saying we're not seeing anything at this time that suggests race is a motive," Biehl said.

The Dayton shooting came less than 15 hours after 20 people were killed and more than two dozens were injured in El Paso, Texas, when a 21-year-old man allegedly opened fire inside a Walmart.

The back-to-back massacres came a week after a gunman killed three people and injured more than a dozen others at the Gilroy Garlic Festival in Northern California.

During his news conference Sunday afternoon, Biehl played the first police dispatch call of an officer reporting an active shooter in the Oregon District as well as several surveillance videos, including one of the suspect being shot to death by an officer. He said five officers and a sergeant ran towards the gunfire and engaged the shooter.

Biehl said Betts arrived in the Oregon District with his sister, Megan Betts, and a mutual male friend. He said at some point before the shooting erupted, Betts and his sister and friend separated.

It remains under investigation what Connor Betts did between the time he separated from his sister and friend, and when the shooting occurred, according to Biehl .

The chief said Megan Betts was among the first victims shot to death.

"It seems to just defy believability that he would shoot his own sister, but it's also hard to believe that he didn't recognize that was his sister. So we just don't know," Biehl said Monday.

On Sunday, Biehl identified the other slain victims as Lois Oglesby, 27, Saeed Saleh, 38, Derrick Fudge, 57, Logan Turner, 30, Nicholas Cumer, 25, Thomas McNichols, 25, Beatrice Warren-Curtis, 36, and Monica Brickhouse, 39.

Biehl said the suspect's car, a 2007 Toyota Corolla, was found parked on the same street where the massacre happened. He said police located a shotgun inside the vehicle.

The suspect legally ordered the .223-caliber rifle, which is similar to an AK-47, and the shotgun found in his car online from a gun dealer in Texas, according to Biehl. He added the weapons were transferred to a firearms dealer in the Dayton area, where the suspect picked them up.

Connor Betts lived in the Dayton suburb of Bellbrook, where FBI and Dayton police executed a search warrant on his home Sunday morning, according to Bellbrook Police Chief Doug Doherty. The chief told reporters that his agency had no previous contact with Betts.

Dana Raber, 20, of Bellbrook, said she was a friend of Megan Betts when they were both high school students.

"She was wonderful," Raber told reporters gathered near the Betts family home in Bellbrook on Sunday. "She was different in a very good way. That's why we got along, I supposed. She's very sweet, had her own opinions and was loud and kind in a way that her brother was quiet and stayed more to himself."

Raber said she was unaware of any friction between Megan and Connor Betts.

"They are a family I admired, and I don't know how they're going to get through this. They were always very nice to me," Raber said.

The shooting could have been much worse, according to Dayton Mayor Ann Whaley, as "thousands of people" were in the Oregon District at the time "enjoying their Saturday evening."

Miami Valley Hospital emergency physician Dr. Randy Marriott said at a news conference Sunday morning that his emergency room received 16 victims from the shooting in the Oregon District. He said four victims were admitted to the hospital, and one was in critical condition.

Marriott said the majority of victims his staff treated suffered gunshots wounds and several patients were injured running from the gunfire. He added that hospital staff received virtually no warning before wounded victims began arriving at the hospital in police cars and ambulances.

The Kettering Health Network, comprised of nine hospitals in Dayton, said multiple victims were also treated at its medical centers. Elizabeth Long, a spokeswoman for the hospital, said nine of the victims were treated at the network's Grandview Medical Center, where three remained in serious condition and three others were in fair condition.

Long said victims were shot in the lower extremities, and some suffered abdominal wounds. One victim suffered a laceration to the foot running from the gunfire.

Asked if she suspects the gunman acted as a copycat of the mass shooting on Saturday morning in El Paso, Texas, that left 20 people dead and at least 26 injured, Mayor Whale said, "I can't speculate on that, frankly. We'll have more to say on that in the coming hours."

Witnesses said the shooting erupted as hundreds of people were lined up outside on the sidewalk to get into nightclubs, or crowded around street musicians performing.

"Most of us can't get to our cars because there are bodies scattered all over across the street from our cars," an eyewitness told Dayton ABC affiliate WKEF. "People that were shot, hit, innocent people — we can't get home to our families now, and those people aren't going home to their families either.”

Whaley said she received several calls from across the country.

"I'm heartbroken," Whaley tweeted Sunday morning. "Thank you to our first responders for all that you've done. We will share updates as we have more information."

In addition to local police, the FBI is on scene assisting with the investigation.

"This is a large scene and investigation. Thank you for your patience," Dayton police added in a subsequent tweet.

Two bars in the Oregon District — Hole in the Wall and Ned Peppers — wrote on Instagram that their staff was safe.

The shooting comes just 14 hours after a gunman killed 20 people and injured over two dozen more at a Walmart 1,600 miles away in El Paso, Texas.

The shooting in El Paso was the eighth-deadliest in modern U.S. history. Five of the top 10 deadliest shootings in U.S. history have occurred since 2016.

President Donald Trump tweeted Sunday morning that the "FBI, local and state law enforcement are working together in El Paso and in Dayton, Ohio," adding that "updates will be given" as more information is gathered in both shootings.

He added in a subsequent tweet, "God bless the people of El Paso Texas. God bless the people of Dayton, Ohio."

During his Sunday mass, the pope referenced the three shootings in Gilroy, El Paso and Dayton, asking worshipers "to join my prayer for the people who lost their lives, the injured and their family members."

"I am spiritually close to the victims of the episodes of violence that have bloodied Texas, California, and Ohio in the United States, striking defenseless people," Pope Francis said.

ABC News' Josh Margolin and Aaron Katersky contributed to this report.

This is a developing story. Please check back for updates.