There are folding knives which use a utility knife blade which are well built, lock open, and would work pretty well for this type of defense.
I'd think a D.A. would have a tough time putting someone away for something with only an inch or so of exposed blade, especially if she said she used it at work opening boxes and claimed she used it to defend herself only because she did not have anything else.
Arizona Senate Bill 1145
Signed into Law 2006
Be it enacted by the Legislature of the State of Arizona:
Section 1. Title 13, chapter 4, Arizona Revised Statutes, is amended by adding section 13-418, to read:
START_STATUTE13-418. Justification; use of force in defense of dwelling, residence or occupied motor vehicles; presumption
A. Notwithstanding any other provision of this chapter, a person is justified in using physical force or deadly physical force against another person if the person reasonably believes himself or another person to be in imminent peril of death or serious bodily injury and the person against whom the physical force or deadly physical force is used was in the process of unlawfully and forcefully entering, or had unlawfully and forcefully entered, a dwelling, residence or occupied motor vehicle, or had removed or was attempting to remove another person against the other person’s will from the dwelling, residence or occupied motor vehicle.
B. A person is presumed to be acting reasonably if the person is acting against another person who unlawfully and forcefully enters or entered the person’s dwelling, residence or occupied motor vehicle, except that the presumption does not apply if:
1. The person against whom physical force or deadly physical force was used has the right to be in or is a lawful resident of the dwelling, residence or occupied motor vehicle, including an owner, lessee, invitee or titleholder, and an order of protection or injunction against harassment has not been filed against that person.
2. The person against whom the physical force or deadly physical force was used is the parent or grandparent, or has legal custody or guardianship, of a child or grandchild sought to be removed from the dwelling, residence or occupied motor vehicle.
3. The person who uses physical force or deadly physical force is engaged in an unlawful activity or is using the dwelling, residence or occupied motor vehicle to further an unlawful activity.
4. The person against whom the physical force or deadly physical force was used is a law enforcement officer who enters or attempts to enter a dwelling, residence or occupied motor vehicle in the performance of official duties and the officer identified himself as an officer or the person using force knew or reasonably should have known that the person was a law enforcement officer.
C. A person has no duty to retreat before threatening or using physical force or deadly physical force pursuant to this section.