Down Arrow Button Icon

Police worked Monday to pin down why a 24-year-old gunman killed nine people, including his sister, in a weekend shooting rampage in a popular nightlife area in Dayton, Ohio.

Connor Betts, who was wearing a mask and body armor when he opened fire in the bustling Oregon District early Sunday, was armed with an AR-15-style rifle. If all of the magazines he had with him were full, which hasn’t been confirmed, he would have had a maximum of 250 rounds, said Police Chief Richard Biehl.

“It is fundamentally problematic. To have that level of weaponry in a civilian environment is problematic,” Biehl added.

Betts’ rampage was the second mass shooting in the U.S. over the weekend, both leaving a total of 31 people dead and more than 50 injured.

Of the more than 30 people injured in Ohio, at least 14 had gunshot wounds; others were hurt as people fled, city officials said. Eleven remained hospitalized Monday, Fire Chief Jeffrey Payne said.

Still unknown is whether Betts targeted any of the victims, including his 22-year-old sister, Megan, the youngest of the dead.

“It seems to just defy believability he would shoot his own sister, but it’s also hard to believe that he didn’t recognize it was his sister, so we just don’t know,” Biehl said.

While the gunman was white and six of the nine killed were black, police said the speed of the rampage made any discrimination in the shooting seem unlikely. It all happened within 30 seconds, before police officers stationed nearby fatally shot Betts.

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

Betts had no apparent criminal record as an adult. Ohio law bars anyone convicted of a felony as an adult, or convicted of a juvenile charge that would have been a felony if they were 18 or older, from buying firearms.

“There’s nothing in this individual’s record that would have precluded him from getting these weapons,” Biehl said Sunday.

Surveillance video showed officers shot Betts at the doorstep of a bar where some people had taken cover. Had he gotten inside, the result would have been “catastrophic,” Biehl said.

Anthony Reynolds, 31, said the first gunshot “was kind of an echo because of the buildings. Then it was rapid, rapid. People were just falling.”

Ohio Gov. Mike DeWine visited the scene Sunday and said policymakers must now consider: “Is there anything we can do in the future to make sure something like this does not happen?”

At a vigil hours later, hundreds of people, mostly young adults, vented their frustration at the Republican governor, interrupting him with chants of “Make a change!” and “Do something!” as he talked about the victims.

“People are angry, and they’re upset. They should be,” said Jennifer Alfrey, 24, of Middletown, who added that she didn’t agree with interrupting the vigil but understood why so many did.

Mayor Nan Whaley, a Democrat, said there would be time later for dealing with policy issues and implored the crowd to honor the victims.

Ohio’s two U.S. senators also visited Dayton. Democratic Sen. Sherrod Brown said stronger gun safety laws are needed, while Republican Sen. Rob Portman said the discussion must include not just policy changes, but issues such as mental health support.

Police have said there was nothing in Betts’ background that would have prevented him from buying the rifle he modified and used in the shooting. They said they also found a shotgun in his car.

Authorities identified the other dead as Monica Brickhouse, 39; Nicholas Cumer, 25; Derrick Fudge, 57; Thomas McNichols, 25; Lois Oglesby, 27; Saeed Saleh, 38; Logan Turner, 30; and Beatrice N. Warren-Curtis, 36.

Conflicting accounts of Betts have emerged, especially from his time at Bellbrook High School, southeast of Dayton.

High school classmates said he was suspended for compiling a “hit list” of those he wanted to kill and a “rape list” of girls he wanted to sexually assault.

Both former classmates told The Associated Press that Betts was suspended during their junior year at Bellbrook High School after a hit list was found scrawled in a school bathroom. That followed an earlier suspension after Betts came to school with a list of female students he wanted to sexually assault, according to the two classmates, a man and a woman who are both now 24 and spoke on condition of anonymity out of concern they might face harassment.

A former cheerleader, the woman said she didn’t really know Betts and was surprised when a police officer told her during her freshman year that her name was included on a list of potential targets.

“The officer said he wouldn’t be at school for a while,” she said. “But after some time passed, he was back, walking the halls. They didn’t give us any warning that he was returning to school.”

Bellbrook-Sugarcreek Schools wouldn’t comment and refused to release information about Betts, citing legal protections for student records.

Bellbrook Police Chief Doug Doherty said he and his officers had no previous contact with Betts and weren’t aware of any history of violence. Sugarcreek Township police said the only records they have on Betts are from a 2015 traffic citation. They noted without further explanation that Ohio law allows sealed juvenile court records to be expunged after five years or when the person involved turns 23.

But others say he was known as a friendly guy who sometimes stopped for a beer or two at a bar southeast of Dayton in Bellbrook, a short drive from his home.

Bartender Andy Baker said Betts was at Romer’s Bar & Grill on July 29 and seemed fine. Fellow customer Mike Kern said he sometimes played trivia there with Betts, who was “the kind of kid you’d want as a son.”

“I never heard him talk about violence, say a racist word, or anything like that,” Kern said.

The Ohio shooting came hours after a young man opened fire in a crowded El Paso, Texas, shopping area, leaving 22 dead and more than two dozen injured. Just days before, on July 28, a 19-year-old shot and killed three people, including two children, at the Gilroy Garlic Festival in Northern California.

Sunday’s shooting in Dayton is the 22nd mass killing of 2019 in the U.S., according to the AP/USA Today/Northeastern University mass murder database that tracks homicides where four or more people were killed—not including the offender. The 20 mass killings in the U.S. in 2019 that preceded this weekend claimed 96 lives.

President Donald Trump said he wanted Washington to “come together” on legislation providing “strong background checks” for gun users, but he gave no details. Previous gun control measures have languished in the Republican-controlled Senate.

Trump tweeted about the weekend shootings: “We can never forget them, and those many who came before them.”

The Democrat-led House has passed a gun control bill that includes fixes to the nation’s firearm background check system, but it has languished in the Senate.

Trump suggested that a background check bill could be paired with his long-sought effort to toughen the nation’s immigration system. He didn’t say how.

During his remarks, Trump at one point erroneously said the Ohio shooting had taken place in Toledo, not Dayton. It followed an error made by former Vice President Joe Biden on Sunday evening, when he described shootings in “Houston” and “Michigan” before correcting himself.

Dayton, Ohio Police Investigating Gunman’s Motive: Did He Target His Sister?

More must-read stories from Fortune: