A valid last will and testament should be signed, but there have been a limited number of cases where an unsigned will is admitted into probate. This was the case with the unsigned will of George Philip Lippi in Philadelphia, Pennsylvania back in 1882 as reported in "The New York Times" and much more recently in 2009, New Jersey probate cases. If a person dies before he can sign a drafted will, proving his intentions prior to death is essential to having the will admitted into probate.
Look for a signed original last will and testament. Some testators will sign only one copy and provide beneficiaries with an unsigned copy as recommended by The Internet Legal Research Group. If a signed copy exists, admitting it is much easier.
Obtain statements of any witnesses who were present when the will draft was written. Cases where someone such as an attorney was hired to write the will or otherwise witnessed a coherent person's instructions to draft a will provide credibility to the will even though it is unsigned.
Go the county court where the deceased resided prior to death and file a petition to open probate and request a hearing to admit the will as valid. Include a copy of the will as well as the death certificate.
Notify all potential beneficiaries of the hearing, giving everyone the opportunity to contest the unsigned will if they disagree.
Attend the hearing to demonstrate the validity of the will. Proof includes statements and live testimony of witnesses.
Obtain court approval admitting the will into the deceased's estate.
Proceed with settling the estate by collecting all assets and debt information. Pay all debts, including estate taxes and probate costs, and then distribute the remaining assets to the heirs as indicated in the will.
Every state has different probate rules and forms. Ask the county court clerk what specific forms are required where the deceased lived.