Dayton Police Chief Richard S. Biehl said that while the shooter's sister "was not the first victim," the 22-year-old "was one of the initial victims"
The shooter, 24-year-old Connor Betts of the nearby town of Bellbrook, died after being shot by police within 30 seconds of opening fire, Dayton Police Department Chief Richard S. Biehl said at a Sunday press conference.
According to Biehl, Megan, 22, traveled with Connor to the downtown area in the same car initially before separating. At 1:05 a.m., Connor opened fire on the streets of the Oregon District, a popular nightlife area.
“Right as [Connor] came out of the alleyway [where the first victim was shot], [Megan] and another male who was a companion of the suspect was shot and wounded,” Biehl said, noting that while Connor’s sister “was not the first victim,” she “was one of the initial victims.”
“So they were victims initially after the first person was shot,” he continued of Megan and her companion.
Betts was a student at Wright State University studying earth and environmental sciences, according to her student profile.
According to her LinkedIn page, she had spent time recently as a tour guide at the Missoula Smokejumper Visitor Center in Montana, which is dedicated to forest preservation and fire prevention.
Daniel Cottrell, her former supervisor at the center, described Betts to The Washington Post as a “very positive person” who was well-liked by her peers.
“We really enjoyed the time that she spent working here for us. She was full of life and really passionate,” Cottrell said. “She was a very caring individual.”
NBC News, citing eyewitnesses, reports the shooting occurred near the Ned Peppers bar. In a Facebook post, the bar said, “We have police regularly staffed next to our business who engaged the shooter and neutralized the threat.”
“Had this individual made it through the doorway of Ned Peppers with that level of weaponry, there would have been catastrophic level of injury and loss of life,” Biehl said Sunday.
Aside from Megan, authorities released the names of the other eight individuals who were killed: Lois Oglesby, 27; Sayid Saleh, 38; Derrick Fudge, 57; Logan Turner, 30; Nicholas Cumer, 25; Thomas McNichols, 25; Beatrice Warren Curtis, 36; Monica Brickhouse, 39.
“We believe he was planning this or something like this for a while,” a source close to the investigation tells PEOPLE. “It’s too soon to speculate on why he acted when he did.”
RELATED VIDEO: At Least Three People — Including Boy, 6 — Killed in Shooting at California Garlic Festival
At a press conference, Dayton Mayor Nan Whaley said the shooter — who also injured 27 — was wearing body armor and carrying a .223-caliber rifle, plus high-capacity magazines.
Whaley said that if not for the quick police response, “hundreds of people in the Oregon District could be dead today,” reports the Associated Press.
The Dayton incident marked the second mass shooting in the United States in less than 24 hours. On Saturday, 20 people were killed and 26 injured in a shooting at a Walmart in El Paso, Texas.
Police arrested a 21-year-old male suspect in El Paso and authorities are investigating the shooting as a hate crime after learning the suspect apparently wrote a manifesto with white nationalist themes, a source familiar with the investigation told PEOPLE.
• With reporting by SUSAN KATZ KEATING