At 1:05 a.m., eyewitnesses reported that a man opened fire at the entrance of Ned Peppers Bar in the downtown Oregon Historic District of Dayton after being denied entry. He was carrying an Anderson Manufacturing AM-15 with a 100 round magazine, and shot into crowds, killing nine people. One of them the victims was his sister Megan.
According to Dayton Police Chief Richard Biehl, 20 seconds after the shooting began, law enforcement officers on the scene engaged the gunman. Within thirty seconds after the first shots were fired, the man was shot dead. Local police evacuated many nearby night venues, and warned Dayton residents to stay away from the Oregon district.
During the day, police and the FBI began searching the shooter's home and found writings that showed interest in killing people. A preliminary assessment of the writings indicated no racial or political motive. One classmate of Betts said he was bullied in high school and that he made a list of people at his school he wanted to kill in 2010 or 2011. The classmate said Betts had planned commit a school shooting, but this plan never came to fruition. According to law enforcement, Betts had no criminal record except for minor traffic offenses.
According to the authorities, the shooter had additional magazines with him, and was wearing body armor during the attack. According to the Dayton police, Betts ordered the semi-automatic gun that he used in the shooting online from Texas, and the gun was transferred to a local firearms dealer in Ohio, where Betts picked it up