SHOOT OR NO SHOOT: Would you employ deadly force and at what point?

For those of you who have already taken your Illinois concealed carry classes (and those who haven’t), we’ve got a video for you.

It’s hard to watch.  A young mother is attacked by another person (turns out it was another woman) who pummels her viciously, and then threatens to beat down the two-year-old toddler who tries to come to his mother’s aid.

Assuming this took place where you’re licensed to carry and are packing your personal safety tool, at what point in this video would you employ deadly force and why?  Consider this an exercise in articulating the threat.

The use of force spectrum can go from “Do nothing, walk away” to “Light that attacker up”.

Where would you intervene and why – in the comments section please.  You don’t have to use your real name and we won’t post your email address.

Thanks.
Here’s the story:

WARNING: The video included in this story is “not safe for work”.  Turn up the volume as their are clues in the audio track…

Salem, NJ (NJ.com)— Police are searching for a woman seen on an amateur video savagely beating another woman as the victim’s 2-year-old son watched and pleaded for the violence to stop.

“Police in this county deal with this type of violence everyday. Yet, this video is physically sickening to watch,” Salem Chief of Police John J. Pelura III said Wednesday.

The suspect in the case has been identified as Latia Harris, 25, of Salem, who is facing charges of aggravated assault and two counts of making terroristic threats, Pelura said. She has not yet been apprehended.

A video showing the violent attack had been posted for a brief time Tuesday night on Facebook before it was taken down. Law enforcement and others were able to obtain a copy of the video.