“I think this just goes so far beyond politics, if we are parents”

“I just instinctually knew there was just absolutely no way I was not going to prosecute them when I heard all the evidence,” Ms. McDonald said in an interview.

Ms. McDonald pointed to what she said is the chilling lead-up to the Nov. 30 massacre: how James and Jennifer Crumbley bought their son a 9-millimeter handgun as an early Christmas present, then failed to tell school officials about it, even after they called the parents to a meeting because a teacher saw their son’s drawing of a gun, a victim and the plea, “The thoughts won’t stop. Please help me.”…

Ms. McDonald, a Democrat, said she has received support for her decision even from Republican gun owners, some of whom have written her letters.

“Lots of gun owners say, ‘Absolutely — if you’re not going to store your weapon safely, if you’re not going to be responsible with it, you should be held accountable,’” she said. “I think this just goes so far beyond politics, if we are parents.”