From what I know, these allegations only came out months after his wife left him. She also got a restraining order against him—well after she left New Hampshire, with the children—which is what led to the police stealing all his firearms.
Obviously, it could all be true, but the timeline of events leads me to believe that this is bullshit she’s making up in order to tilt the divorce proceedings in her favor. Claiming that one “fears for one’s safety” against one’s ex is almost automatic in divorce proceedings nowadays, and is usually recommended by sleazy divorce lawyers in order to move things along favorably. Allegations of child abuse come in second as the quickest way to streamline things.