Whos responsible

Your question is unclear regarding (a) who entered and (b) for what purpose, as well as whether this is a residential or commercial lease. Presuming that it is a residential lease, most residential leases define the rights of entry in the Lease Agreement. Furthermore NRS 118A.330 defines that Landlords shall have access to the dwelling unit and that Tenants shall not unreasonably withhold consent to allow Landlords to (a) inspect the premises; (b) make necessary or agreed repairs, decorating, alterations or improvements; (c) supply necessary or agreed services; or(d) show the dwelling unit to prospective or actual purchasers, mortgagees, tenants, workers, contractors or other persons with a bona fide interest in inspecting the premises.  Furthermore Landlords are allowed to enter without consent in cases of emergency.  Landlords cannot abuse these rights of access and are expect to give Tenants at least 24 hours notice (except in cases of emergency). While the Landlord may have rights of access, you may have a claim for the wrongful theft of your personal property by the Landlord or its agents.  The issue is going to be with being able to prove that the Landlord is the actual culprit who took the missing items.  You may be ahead to to check with your renters insurance (if you have such coverage) for theft coverage.