The story I read last night was that the police were "approaching the house" when the woman shot at them. Somebody is lying.
Unfortunately for the truth, the ONE potential witness for the other side is dead.
For this 92 year-old women to have gotten off 3 shots that found their marks, she and her targets almost certainly had to be well within that 21' range where most gunfights take place. I rather doubt the cops were "approaching" the house. My guess is that they made a racket coming on to her porch, quickly took out the door, she had her weapon handy -- thanks to the cops' inability to secure her neighborhood -- and let fly.