Litter training adult cats

Question
Ok this is a complicated problem so i hope you're ready.

   We live out side of town and had 7 cats (5 of which are male) and after a year or so are neighbor started shooting at them. He managed to kill one of our females. We were very concerned for their safety so we decided to make them inside cats but we can't seem to get them to use the litter box. All of them are spayed/neutered and we really need help to get them to stop peeing and pooping all over.
  My family and i have considered giving them away but we can't seem to bring ourselves to do it. We love these animals very much and would love to get some help making them house friendly.

Thank-you very much!!

Answer
Aubrey,

Poor kitties! I don't know where you live, but there are laws against shooting or harming other people's cats. There is a good book out about Cats and The Law. You should be able to do something to control your neighbor, including filing a complaint. He could also hit a child trying to shoot a cat. I would take action to stop him so your cats could be happily outside cats again.

Cats will pee and poop all over when they are very stressed. It could coming inside from being used to the outside.

I would get a litterbox and put some of the dirt they used when they were outside. If they use it, then start adding litter to it slowly until they get used to litter.

You probably need to use a few litterboxes in different areas. Some cats like privacy, and some cats don't want to be ambushed when they go.

I am also including some links about improper litterbox use that you may find helpful:
(copy and paste, or type, the whole link into your address bar)

http://cats.about.com/cs/behavioralissues/a/outsidebox_two.htm

http://www.geocities.com/heartland/pointe/9352/litterboxhelp.html

http://www.apbc.org.uk/article10.htm

http://www.secretsofcats.com/behavior/peeing-pooping-problems.html

I hope these help, and I'm sorry about your kitty.

Tabbi