[taltos]

The problem with the non lethal options are that they are generally single shot and/or require you to get too close to their intended target. This person is a rabid animal and there is only one solution; deadly force. If your MIL would feel better about it, have her get a 28 ga shotgun and use that instead of the 12 ga. This will stop the target and would be considered to be more survivable. A well trained personal protection dog would be another option. German shepards or Bouviers are the more stable breeds for this purpose.