The 17-year-old who opened fire at a high school in Santa Fe, Texas, and killed eight students and two teachers had allegedly been publicly embarrassed by one of his victims after months of making aggressive advances, her mother said. Shana Fisher “had 4 months of problems from this boy,” her mother, Sadie Rodriguez, told the Los Angeles Times. “He kept making advances on her and she repeatedly told him no.” Dimitrios Pagourtzis apparently got more and more aggressive in his advances toward the 16-year-old girl until she finally stood up to him in class and embarrassed him publicly. “A week later he opens fire on everyone he didn’t like,” Rodriguez wrote in a message to the newspaper. “Shana being the first one.” It isn’t clear how Fisher’s mom knew her daughter was Pagourtzis’ first victim.

Some have raised questions about Rodriguez’s claims, Los Angeles Times reporter Matt Pearce acknowledged on Twitter Sunday afternoon. “Other family friends have raised questions about the reliability of her claims and say they haven’t been able to corroborate her accounts about the shooter’s behavior toward her daughter,” Pearce wrote. The mom was allegedly “largely out of her daughter’s life” and some are questioning “how she would have learned details like that.”

FYI: Since Shana’s mom started talking to reporters, other family friends have raised questions about the reliability of her claims and say they haven’t been able to corroborate her accounts about the shooter’s behavior toward her daughter. We’ll keep you posted if we learn more. https://t.co/u2lfdZuUzK — Matt Pearce 🦅 (@mattdpearce) May 20, 2018

They’re saying that the mom was largely out of her daughter’s life, and so they’re asking how she would have learned details like that. More broadly, regardless of the source, it’s important to note if anyone’s claims can’t be corroborated. https://t.co/Vs013UbyJq — Matt Pearce 🦅 (@mattdpearce) May 20, 2018

Beyond the specifics of that one victim, in an affidavit authorities said Pagourtzis was at least partly meticulous in who he decided to kill as he allegedly said “he did not shoot students he did like so he could have his story told.” As more witness accounts are coming forward it is becoming clear that Pagourtzis seemed to take a bit of joy out of taunting students. Pagourtzis apparently yelled “Woo-hoo!” while shooting, for example.

Authorities said they are still trying to parse together the clues to figure out a motive for the shooting. Pagourtzis’ family issued a statement saying they were “saddened and dismayed” by the shooting and “as shocked and confused as anyone else by these events.” The family said that while they are “mostly in the dark about the specifics” of what took place, “what we have learned from media reports seems incompatible with the boy we love.”