The Grinch who stole christmas....LITERALLY!

As I have stated before, I have 6 kids: two from his previous marriage, two from mine and two together. The two from his live w/ the mom but visit often and were with us for the holidays. His two are a boy-13 and a girl-12. During the visit I noticed random things missing, razors, lotion, etc. But with 6 kids in the house no biggie right? Until some money came up missing...That's when dad decided to check through his daughters luggage just to be sure nothing inadvertently got packed. Me....I did not think for a single moment that anyone had taken items. As dad began to unpack the luggage it was discovered that my step daughter had stolen about 20 items from our home. Items ranging from shoes, to cosmetics, to clothes, to lighters, flashlights, money etc. I was deeply hurt and horrified! When confronted my daughter just said nothing but did not appear remorseful at all. My fiance got all big and bad and said he was gonna definitely discipline her but then decided that having her apologize was punishment enough! My hurt over the theft was quickly replaced by anger at my fiance for not giving her some sort of consequence. Not only was she let completely off the hook but all the other kids in the home who were also stolen from were outraged! I'm not exactly sure what should have been done although I do know that since she had sooo much it could not have possibly been her first time. Now, it is not uncommon for dad and I disagree on how to handle the kids when there is an issue. I am more strict where he just takes a kinder, gentler, more INEFFECTIVE approach. But this was just ridiculous. Not only did we all feel violated having our property stolen but then not even having any sort of justice served was just, to me, encouraging that sort of behavior. It has been very difficult to explain to my biological kids why she was let off so easily and bringing it up with him just seems useless because he gets soo offensive. Since that incident I just completely lost respect for him as a father. And feel betrayed by him as well as her. Suggestions anyone?