In the hours before the mass shooting here, Connor and Megan Betts, brother and sister, drove the family's 2007 Corolla together to this city's historic Oregon District, an area alive on a summer night with restaurants, bars and nightlife.
Then, police said, they separated.
It is not clear what Megan, 22, did at this point. But Connor, 24, donned a mask, body armor, ear protection and, wielding an "AR-15 like" assault weapon with magazines containing 100 rounds, set out on a street rampage that, while it lasted less than a minute, claimed the lives of nine people and injured 27 others.
Among the first to die was Betts' sister Megan. Her male companion was also injured, but survived.
Less than a minute into the barrage, police patrolling the area "neutralized" Betts - he was shot to death - as he was about to enter a bar where dozens of people had run into hiding. A bouncer was injured by shrapnel. At least six policemen fired rounds at the suspect and had they failed, many more are likely to be dead, officials said.
"As a mayor, this is a day that we all dread happening," Dayton Mayor Nan Whaley said in a Sunday morning news conference. "And certainly what's very sad as I've gotten messages from cities across the country is that so many of us have gone through it."
The attack came less than a day after a man with an assault-style weapon killed 20 people in El Paso, Texas, and a week after a gunman fired on a garlic festival in Gilroy, California, killing three people and wounding 12.
Authorities said that in Dayton four women and five men were killed. Of the 27 people who were injured, 15 have been discharged from the hospital.
Exactly what precipitated the chaos is unknown.
The guns had been legally purchased, police said, and there was nothing in Connor Betts adult criminal background that would have raised concerns - he'd only had traffic tickets for speeding and failure to yield.
Dayton Police Chief Richard Biehl said they are still trying to answer "the question that everyone wants to know: why?"
Betts had been studying psychology at a local community college and working at a Chipotle restaurant. In an online profile, Betts reportedly described himself as "Good under pressure. Fast learner. Eager to overachieve." But Betts also had been troubled in high school, at one point drawing up a "hit list," and such incidents, along with his relationship with his sister, will be points of interest for the investigators.
The shooting shattered a typical summer weekend night's revelry in Dayton's Oregon District, an area east of downtown that was busy with the nightlife of bars and restaurants.
Pulling up to the area that night with the Betts was a male "companion," police said, and the trio parked just a few blocks away from where the shooting would begin.
At some point, Connor Betts diverged from the group.
"What they did during that time they weren't together is a question mark," Biehl said.
Before the first shots rang out, it was a night of celebration for the interns from the Maple Tree Health Alliance, a cancer treatment center.
One of them was Tyler Erwin, 27, who was standing in line to the Ned Peppers bar with his girlfriend, Mary Pelphrey, and three fellow interns when they heard the shots as Betts shot first in an alley and then many more times on Fifth Street. Video recordings of this time show people fleeing past parked cars as shot after shot rang out.
Erwin grabbed Pelphrey and dove behind a doorway next to the opening of the bar. For a minute, all they heard was more gunshots and the sounds of people screaming, Erwin remembered.
After what felt like hours, the couple emerged."There was just bodies, blood everywhere," he said.
One of their friends, Hannah Martin, had been shot in the leg, Erwin said. Another, Kelsey Colaric, had been shot in the abdomen. The third, Nick Cumer, was on the ground, rolled over on his side. The 25-year-old has been confirmed as one of the victims who died at the shooting. Cumer had been a graduate student in the master of cancer care program at St. Francis University in Pennsylvania and spent the summer living in Columbus and commuting an hour each morning to the Alliance's treatment center.
"Nick was an extraordinary human being. He was intelligent, he was extremely caring and kind. He loved his patients, and he always went above and beyond for them," Erwin said. "We were going to show him one good, fun night out...That was the plan."
Belinda Brown, a 46-year-old elementary school teacher in Dayton, told The Washington Post that her niece was sitting outside a restaurant when the shooter, clad entirely in black and wearing a mask, pulled out a large gun and "just opened fire." Her niece jumped up with her friends, ran inside and hid behind the counter of a nearby bar, where she huddled in terror with the bar's employees, said Brown, who heard the account later.
The niece, her friends and the employees were able to sneak out the back, she added.
Brown's nephew, meanwhile, was at a club next door to the restaurant where the shooting started. As soon as he heard the loud pops, he whipped out his phone and started recording - and running.
"Nothing ever happens in the Oregon District. It's a very quiet, upscale neighborhood in Dayton, and everybody hangs out there," Brown said. "It's just unheard of. You don't even get fights there."
Megan was not Connor Betts' first kill, according to police. But she and the male companion were among the earliest victims, fatally shot around when Betts emerged onto Fifth Street.
Police said officers ended the violence "quickly" by shooting the gunman, who began firing about 1:00 a.m.
Surveillance footage from outside the Oregon District's Ned Peppers Bar captured the moment Betts was struck multiple times by officers' fire as he tried to enter the establishment. Police said they neutralized Betts in 30 seconds.
"Had this individual made it through the doorway of Ned Peppers with that level of weaponry, there would have been catastrophic injury and loss of life," Biehl said. "So stopping him before he could get inside there - where you saw people were running in there for protection - was essential to minimizing to the degree we could casualties and deaths from this incident."
Injuries ranged from gunshot wounds to the abdomen and extremities to a foot laceration suffered in the chaos after the shooting, officials said. One of the survivors was in critical condition on Sunday afternoon.
Because the investigation is in its early stages, Biehl said, "any suggestion of motive would be irresponsible." But they will seek to find out what happened.
A LinkedIn profile that appears to belong to Connor Betts indicates he was a psychology student at Sinclair Community College in Dayton and an employee at Chipotle Mexican Grill.
Though his criminal background showed little beyond traffic tickets, according to former high school classmates, Connor Betts developed a "hit list" of classmates he wanted to harm in high school and was "always obsessed" with guns.
Midway through Connor Betts's freshman year, school officials caught him toting around a notebook that contained a "detailed" plan laying out how he was going to hurt several classmates, many of whom were women who had rejected him sexually, according to a woman who went to school with him who spoke on the condition of anonymity.
Soon after that, Connor Betts left school for a year, though he eventually returned and graduated, the woman said. She added that Connor Betts never seemed interested in extreme ideologies, nor did he seem racist -- but he "always had a problem with women."
Bellbrook High School officials could not immediately be reached for comment.
Also unknown is the nature of the relationship with his sister. Megan Betts had spent the last few months of her life as a tour guide helping visitors explore the wilds of Missoula County, Montana, said her former supervisor at the Smokejumpers Visitor Center.
Megan Betts scored the summer internship - which ran from roughly the middle of May to July 2019 - through a program run by the Student Conservation Association, according to Daniel Cottrell, the manager at the visitor center.
He said Megan Betts was a "very positive person." While she worked at the visitor center, she earned a reputation as a competent employee well-liked by her peers, according to Cottrell. She also loved exploring new places - especially Montana and its "local culture," he said.
"We really enjoyed the time that she spent working here for us. She was full of life and really passionate," Cottrell said in an interview with The Post. "She was a very caring individual." Cottrell said that he never discussed her brother with her but that she did seem close with her family.
When Megan Betts left the job in Montana near the end of the summer, her mother drove to pick her up, and Cottrell noticed the two seemed to have a very good relationship.
"I'm just sad," Cottrell said of the Dayton shooting. "I am just frustrated these things keep happening in this country."
The quiet cul-de-sac in a leafy suburb of Dayton where Betts's address is listed was turned upside down Sunday when news of the gunman's identity spread. Brad Howard, 24, told The Post that he attended school with Betts and described his former classmate as soft-spoken.
Whaley would not speculate on the gunman's motive. "I can't get inside his head," she said.
The Montgomery County Coroner's Office identified the nine as Megan K. Betts, Monica E. Brickhouse, Nicholas P. Cumer, Derrick R. Fudge, Thomas J. McNichols, Lois L. Oglesby, Saeed Saleh, Logan M. Turner and Beatrice N. Warren-Curtis. A vigil for victims and their loved ones will be held at 8 p.m. Sunday in the Oregon District on Fifth Street.
"While this is a terribly sad day for our city, I am amazed by the quick response of Dayton police that saved literally hundreds of lives," she said.
Just hours after the shooting, the scene was cordoned off with police tape and the area was largely deserted. But as daybreak settled over the city, more and more people filed into Dayton's convention center seeking information about missing loved ones at a station set up by the city.
Joe Oglesby, who said his niece, Lois Oglesby, was killed in the attack, said he felt "numb." Oglesby said his 29-year-old niece had just had a baby last month and had an older child.
"She was a nurse's aide and a very devoted mother," Oglesby said.
The shooting is one in a string of high-profile challenges the city has faced this year. A Ku Klux Klan rally drew hundreds of protesters to the city in May, followed by a round of tornadoes that chewed through the northern part of the city.
"Dayton has been through a lot lately, but I continue to be amazed at the grit and resiliency of the community," Whaley said.
The governor ordered flags to fly at half-staff as people from around the world expressed sadness over the latest mass shooting in the United States. Pope Francis offered his condolences for the victims of U.S. shootings that hurt "defenseless people." New British Prime Minister Boris Johnson tweeted out his sympathy, too.
President Donald Trump was briefed on the Dayton shooting and is monitoring the situation, deputy White House press secretary Steven Groves told The Associated Press.
Trump's first tweet on the shooting Sunday morning focused on law enforcement's response, praising the speed, and said that "information is rapidly being accumulated in Dayton."
"Much has already [been] learned in El Paso," he wrote.
"God bless the people of El Paso Texas," he added in another tweet. "God bless the people of Dayton, Ohio."
Ohio leaders also shared their grief. Some went beyond condolences to call for stricter gun control, echoing Democratic leaders who renewed their condemnations of inaction on guns after the El Paso shooting.
"We are also angry - angry that shooting after shooting politicians in Washington and Columbus refuse to pass sensible gun-safety laws to protect our communities," Sen. Sherrod Brown, a Democrat, tweeted.
Sen. Rob Portman, R-Ohio, did not mention gun control but said in a statement that these "senseless acts of violence must stop."
Gun owners can carry their weapons openly in Ohio; concealed-carry handgun licenses are available through an application. The minimum age to purchase a gun is 18, while an individual must be at least 21 to buy a handgun.
Rep. Michael Turner, R-Ohio, wrote on Twitter that his daughter and a friend were across the street from the site of the shooting when it began. They watched as officers ran toward gunfire, he said.
"Thank you to @DaytonPolice for their bravery in stopping this evil," Turner said.