No, you may not. The trailer is still his property: even if you know your stolen property is there, you are not allowed to trespass in it, and if you do, *you* could be charged with breaking and entering.Here is what you can do to get your items back (besides, of course, pressing charges for theft): you can seek an order to show cause on an "emergent" (think: "urgent" or "emergent") basis in county court allowing you to recover your items and authorizing law enforcement (e.g. the sheriff) to assist you in recovering these items. With a court order authorizing recovery, you can do this legally. Ideally, seek an attorney to assist; if it's not economically worth (given the items' value) doing this, you can do so on a "pro se" (as your own attorney) basis--go to the court clerk's office and explain that you want an order that someone return items of yours that you know are in his trailer.