Legal Question in Criminal Law in California

Re: other persons property in my posession

No, and you also can't hold onto the part that doesn't belong to your son against the owner's wishes.

Our legal system usually frowns upon people who resort to self-help, especially when they do it in the first instance. One reason for this is that people who have been injured often feel they are entitled to exact more revenge than a neutral party would consider fair; the object of their revenge then feels wronged and wants revenge, too. The cycle repeats and the process escalates. We have courts and police precisely in order to provide a more civilized alternative.

I presume the party was held without your permission. I also presume that you don't know who committed each act of vanadalism and theft. It therefore sounds like you are holding on to property which may belong to an entirely innocent person, and I don't see how you can justify doing so.

Although I doubt it will come to this, the owners of the items you are holding can successfully sue you for their return. It is more likely that they will ask the police to recover the items from your home. If you know who caused the damage you can take them to court and/or ask the police for help. If you don't know who did it, you can't just lash out at whoever happened to leave some property in the nouse. You can punish your son if he is still a dependent (perhaps having him work off the debt would be appropriate) but you can't punish the others yourself -- especially if you can't demonstrate that they are responsible for your losses.