Another magic gun! Probably the Amish again.
You do realize, that the trigger pressure needed to discharge a sa pistol is 4-5 lbs or less right? and can be as low as 2-3lbs.
A loaded pistol in a backpack, easily could be set off by something shifting in the backpack if it bumped the trigger.
A school resource officer and teacher said they recovered the gun right after it went off.
= = =
If it went off my itself, I’m not sure I would want to try to recover it.