If you've ever wondered about the public perception of "assault" rifles, you are not alone. Antis come up with these labels for guns that makes them seem more "evil" than they actually are. And what makes an "assault rifle" and "assault rifle?" The similar LOOK to a select-fire military rifles.

Nothing about them makes them actually more dangerous, just percieved as more dangerous. This perception is carried over in to court. Glenn Meyer has written an article on how the type of gun you use can affect how you appear in court.

http://www.astcweb.org/public/publication/article.cfm/1/21/5/Weapons-Issues-and-the-Fears-of-the-Legally-Armed-Citizen

Good article!

Here are the cliff notes:
- The percieved purpose of the gun plays directly into sentencing.  You're better off using a pistol than a rifle, better a hunting rifle than an "assult" rifle. 
-Women are harsher jurors.
-Women who use firearms in self defense violate social gender norms, and generally get a higher sentence than men. 

So, for self-defense you're best off using a pistol (the most non-frightening one you own).  And if you do use your firearm, shoot the assailant dead so the only testimony heard by the jury is yours, because juries are stupid.     

Mas Ayoob has said that you shouldn't use reloads for self-defense for some of the vary dame reasons. He feels that juries are prejudical towards those that may be protrayed by the prosecution as creating "super duper lethal" rounds. He notes that any prosecuter worth his salt will use whatever they can to portray the defendant as blood thirsty and just itching to use his gun, but that the job will be much easier if you used reloads. Ayoob recommends using whatever ammo the local LEOs are using so that you can use that fact on your behalf. After all, no one faluts the police for using the most effective loads they can, so use what they do....

That makes a lot of sense Hicarry.  I would think the prosecution would also make an issue out of caliber:  "Why did you use a .45 to shoot my client?  .45's are clearly more lethal than a 9mm or .22.  By using such a caliber, your intent was to kill or maim my client, and not merely stop him."

There is a bit of truth to that concept, as was evident in the Harold Fish case in Arizona. Part of the Prosecution's case was that Fish had used a 10mm handgun.

FYI...the prosecution is "side" that would try to make that argument ("why did you use a .45 to shoot...") and the defense would be representing the shooter...

Ah, typo.   

So the conclusion would be, for self defense use:
- A pistol
- the same factory made ammunition as the police (no reloaded rounds)
- a light caliber

I would also venture that the pistol should be as close to stock as possible with no additional sights, optics, lights or lasers based on the idea that after market parts would increase the precieved lethality or lethal intent of the weapon?

We can't use the same amount of rounds as the police

We cannot use the same number of rounds in a magazine, but we can use the same type of ammo...In terms of "use a light caliber" I would suggest, based on the Harold Fish case, is not to use a "light" round, but to use a common round. The argument in Fish's trial was that the 10mm round was unusual and was somehow much more lethal than a more common round.