Your commercial lease agreement should give you the remedies for how you may terminate the lease agreement and on what notice. The police might be willing to take care of the squatter issue, if it's clearly not a residence. If they won't, you'll definitely want to talk with an attorney.
Yelling at neighbors is not generally grounds for a 24-hour notice to terminate a lease. Regardless, if she's a tenant, you cannot get her out today. Even if there is enough notice, you will likely need to file for an eviction and present your case in court before you get a court order for possession (known as an FED).
But as mentioned, a 24-hour notice probably won't work, because yelling isn't the kind of extreme behavior prevented by that type of eviction. You will likely need to give a...
If the pour over will funds the trust, then the assets in the estate get transferred to the trust and then distributed in accordance with the terms of the trust document. If only mother's portion of the trust (the "A" trust) exists because the B trust wasn't funded, that will provide for the distribution of the trust assets by the successor trustee. The executor and/or trustee should meet with an attorney, preferably the attorney who did the estate planning.
Depending on whether your oral sublease agreement is valid, you might not have any authority to terminate his lease at all--usually that is only the right of the landlord. You may want to talk to the landlord and if you cannot get his cooperation you will certainly want to consult with an attorney in private to figure out the best way to proceed.
What's scheduled in April 2013? If the squatter isn't on your property, why is your liability insurance involved?
It's true, police will rarely respond to remove someone while there is a civil complaint or a colorable claim that a lease, tenancy, or other right to occupy exists. And it's also true that you cannot file an eviction against a neighbor's tenant. If the tenant is on your property, then yes, you can possibly file an eviction.
Frankly, there is too much going on here for you to...
You can file a FED (eviction) complaint seeking possession of the property without further notice to tenants alleging that their notice to you as the basis for the lease being terminated. If you have not evicted a tenant before having a lawyer represent you (or at least consulting with one) is recommended. You can separately sue in small claims court for unpaid rent or other damages.
Perhaps. An ex sister-in-law would not ordinarily inherit anything absent a will. Oregon has no common law marriage. If you didn't marry or have him adopt your kids, then without a will he's a legal stranger, even as a housemate.
If you're already involved in litigation because a suit has been filed, you should talk to an attorney soon. You may be able to claim that his things were actually owned jointly by you, or were owned subject to a debt that he owes you, even without great documentation.
I agree with Mr. Frederick, if all you were left was $500, then this is not worth litigation. But without a copy of the will, how do you know you were left $500? If there is a no probate estate open, then there's no one to show you the will, and if there is a probate open, then that county courthouse will be where it was filed. You can get more help from an attorney, but without an expectation of more than $500, it might not be a good use of your money.
I'd add a bit to the questions of Mr. Pippen. Was the van titled in the trust? How is it titled? Who is the trustee of the trust? When you say you *need* to see it ASAP is this to pay a cost of the administration of the estate or trust or because you personally need money? Will the estate's debts exceed its assets? If you sell the truck and spend the money, how are creditors, heirs and beneficiaries likely to respond? Are they likely to come after you or are you working together?