I believe that she probably received no notice when her animals were taken the first time in 2004 before the court order that she never own animals again.  
There is a certain level of abuse at which they put the lives of the animals above the right of ownership and just take the animals.  If they believe the animals will die if they don't take them right away then they just take them.
I also believe they took the head of the horse.  It was probably so bad they couldn't even get it on a trailer to take it to the state vet.  
That said, I think that this mentally ill woman deserved more than to come home to that.  They should have left a police detail there to take her in, or at least explain what had happened.  Imagine the trauma of finding that horse body to a woman who loves animals literally to death?  That trauma caused her to react this time with a stun gun.
The situation last time could have been handled with care and compassion for her mental illness.  Someone could have been there to meet her when she showed up and softened the blow, let her know that her surviving animals were being given care and would find good homes.  Gotten her some assistance, a friend or loved one to care for her through the night, help her understand the reality of the situation.  Instead she built her own reality in her head to match the one she had of her "idealic farm" with beautiful animals surrounding her.
Reality she had a farm full of torturned animals who were suffering and dying.  In her mind she had a beautiful farm full of fourishing animals who loved her as much as she loved them.  The animal control, peta and the police stormed in and stole her animals and butchered her horse.   When she stunned that police officer she was still living in that delusion.
It amazes me that she had no court ordered psychiatric help.  No follow up care at all?  She was not on an animal control watch list?  Where was her family in all of this?
There are many victims in this situation.  The animals are the obvious victim.  The police officer is an obvious victim.  However, this woman is a victim too.  Mental health just isn't taken seriously enough in this country.  She needs help before she is holding herself hostage in her house full of cats, dogs, chickens, pigs and whatever else she can fit in there with a shotgun waiting for the police to charge the house.
Laney
Mental Illness is nothing to be ashamed of, hiding it in a closet is.