The man who shot dead nine people in the US state of Ohio had been exploring violent ideologies, US investigators announced on Tuesday.
The FBI opened a probe into the motivations of the 24-year-old and were skeptical of a racist motive, the domestic intelligence agency said.
"We have found very specific violent ideologies that the shooter we know followed and was interested in," FBI agent Todd Wickerham told reporters.
Wickerham said there was no evidence the attack was racially motivated, despite six of his nine victims being black.
The shooting happened on the same weekend as a massacre at a Walmart store in El Paso, Texas. In total, 31 people were killed across both mass shootings.
Trouble with women
Several friends of the man told US news outlets he had a history of troubling attitudes and behavior towards women.
A longtime acquaintance of the shooter told The New York Times "he was kind of hateful to women because they didn't want to date him."
The Dayton Daily News reported the shooter had been suspended from his high school for drawing up a "hit list" of girls.
Demoy Howell, a friend of the shooter, told the newspaper that he was "always a bit of an oddball."
"He had a dark sense of humor — jokes about people dying," he said. "He would wear all black. I remember sensing a dark energy around him.
"I think this is less of a hate crime and more of an 'I hate everybody' crime," Howell said.
Associates speak out
The man was reportedly a member of "pornogrind" heavy metal band Menstrual Munchies, with lyrics that revolved around sexual violence. Vice News interviewed a former bandmate of the shooter, who said he had performed live vocals for the band, which released albums such as "6 Ways of Female Butchery."
The pornogrind scene has been described as misogynistic and male-dominated.
His bandmate denied the songs were serious, saying he was shocked at the violence.
A woman who claimed to have briefly dated him earlier this year wrote online that he had "dark thoughts," including about wanting to hurt people. Adelia Johnson, 24, said they met in a college psychology class and bonded over dealing with mental illness.
She claimed that the shooter had shown her a video of the Pittsburgh synagogue shooting on their first date. She said he had "uncontrollable urges" that she called "red flags," which led to her breaking up with him in May.
US President Donald Trump was due to visit the town on Wednesday, as well as El Paso.
Meanwhile, the FBI also said they were investigating the motives of the 19-year-old who targeted a garlic festival in California, killing three people.
aw/se (AFP, Reuters, AP)