*The killers were never identified. She’s got no idea who they were, whether they’ve ever been arrested before, or whether any of her statements are true. She assumes the statements are true, though. Just like she assumes it’s been a long time since anyone told that black boy in the restaurant that he was special.
It’s entirely likely that his mother told him that right before he left for work.
It’s just as likely that it’s been a long time since anyone told the kids on her (very white) block that they were special.