The FBI is conducting an investigation into the gunman who killed nine people in Dayton, Ohio, on Sunday Aug. 4.

Special Agent Todd Wickerham, head of FBI in Cincinnati, said they will try to determine what motivated 24-year-old Connor Betts to kill, if he had any accomplices, and why he chose the time and place he did to murder innocent victims—including his own sister, Megan Betts, 22. At least 27 others were wounded during the gunman’s rampage. “It seems to just defy believability that he would shoot his own sister,” said Dayton Police Chief Richard Biehl, at a media briefing on Aug. 5. “But it’s also hard to believe he didn’t recognize that was his sister, so we just don’t know.”

Biehl said Betts had “violent ideations that include mass shootings and had expressed a desire to commit a mass shooting.” He added there was no evidence to date that the shooting was racially motivated, nor that he was influenced by the mass shooting in El Paso hours earlier.

Authorities work at the scene of a mass shooting, on Aug. 4, 2019, in Dayton, Ohio. (John Minchillo/AP Photo)

Adelia Johnson briefly dated Betts earlier this year, after connecting at a psychology class at Sinclair Community College in Dayton. Johnson said they both struggled with mental illness issues. He took her to a shooting range on a date, and often talked about mass killings, Johnson said in an interview on “The Today Show.” “This isn’t about race, this isn’t about religion, it’s none of those things. This is a man who was in pain and didn’t get the help that he needed,” said Johnson.

“He would have known that his actions were deplorable,” she said of Betts.

Betts performed with an extreme heavy metal band known for their sexually violent lyrics.

Johnson said, looking back she believes there were red flags. She broke up with him via a text message after she had accompanied him to another ex-girlfriends house to drop off an anonymous note that read: “You can’t escape your past.” His fixation on his ex became “the final red flag,” to leave him she said telling friends she was worried.

Mourners gather at a vigil following a nearby mass shooting, on Aug. 4, 2019, in Dayton, Ohio. Multiple people in Ohio have been killed in the second mass shooting in the United States in less than 24 hours. (John Minchillo/AP Photo)

“I wasn’t entirely surprised that he did something bad, and that he ended up on the news. I just didn’t think it would be for this.” It was on the couples very first date that Betts produced footage of the synagogue shooting in Pittsburg that was in the news at the time, to show her.

“The second one, was when he got super drunk, and told me he wanted to hurt people,” Johnson said.

Theo Gainey a former Bellbrook High School classmate and neighbor said Betts was often in trouble at school for threatening others. He was suspended after a hit list of names was found scrawled on a restroom wall. He recalled there had been a big threat. “After the big threat, it kinda followed him. People didn’t really want to hang out with him much, for a kind of an understandable reason. He seemed kind of dangerous,” Gainey said, as reported by 10TV.

“Kind of a loner, bit of an outcast,” he told Today. “Lot of people saw kind of a dark side in him.”