This action was brought by the Phoenix Savings Bank and Trust Company, plaintiff below, as guardian of Ida Grant, an incompetent, against Mollie J. Martin, defendant below and hereinafter referred to as appellant, to cancel a deed executed on the 9th day of February, 1948, by Ida Grant to Mollie J. Martin; and to have the property 'revested in the grantor on the ground of her incompetency at that time. Pending trial in the lower court Gussie Wood was substituted as guardian of the estate of Ida Grant, and will be hereinafter designated as appellee.
The facts out of which this suit arose are that in 1937 appellee and her husband rented a house from Ida Grant which is situated on the land which is the subject of the deed in question. In 1940 Ida Grant commenced living with the Martins in that house. On February 9, 1948, Ida Grant executed to appellee a deed to the land and house thereon, at that time Ida Grant being a widow some eighty years of age. Subsequently appellant ■ did, on June 30, 1948, file a guardianship petition in the superior court of the county of Maricopa urging “That for the past two (2) years the said Ida Grant, by reason of old age, has been mentally incompetent to manage her own affairs. That she has not known the nature and extent of her property or the material objects of her bounty,” and prayed that a guardian be appointed so she could, reconvey the property to Ida Grant. On July 14, 1948, appellee appeared before the above court in the guardianship proceedings of Ida Grant and under oath testified to the truth of the matters alleged in said petition. On that. day Ida Grant was adjudicated to be an incompetent and 2 days later letters of guardianship were issued to the Phoenix Savings Bank and Trust Company.
The pleadings and the evidence disclose that in the lower court appellant denied that’ Ida Grant was incompetent at the time she executed the deed, and alleged *459 that at said time Ida Grant was fully competent to manage her own affairs. The lower court, sitting without a jury, ruled that the deed was void by reason of the incompetency of the grantor, Ida Grant, and set it aside.
Appellant assigns eight errors to the trial court which may be summarized as follows : (a) insufficiency of the evidence to support the judgment; (b) the admission of incompetent, irrelevant and immaterial evidence. Those assignments have been considered but are without merit. Furthermore it will not be necessary to treat them because the case may be disposed of under the doctrine of judicial estoppel.
Under the doctrine of judicial estoppel or “estoppel by oath” appellant was estopped from claiming under said deed and from disputing the allegations in her petition for appointment of guardian for Ida Grant and her testimony in the guardianship proceeding in support of said petition.
The general rule of judicial estoppel is stated in 19 Am.Jur., Estoppel, Sec. 74, p. 712: “It is a general rule that a party is bound by his judicial declarations and may not contradict them in a subsequent action or proceeding. * * * ”
The rule is also laid down in 31 C.J.S., Estoppel, § 119, p. 381:
“As a general rule, a party who has assumed a particular, position in a judicial proceeding is estopped to assume an inconsistent position in a subsequent proceeding involving the same parties and questions.
“The general rule as to estoppel to assume inconsistent positions in judicial proceedings generally * * * has been expressly stated to apply, or has been applied, so as to estop a party to assume inconsistent' positions in successive proceedings. For this doctrine to be applied, it is commonly required that the parties be the same, and that the same questions be involved. * *”
And in 31 C.J.S., Estoppel, § 117, p. 378: “ * * * The elements of reliance and injury which are éssential to the operation of equitable estoppel do not enter into ju: dicial estoppel, at least not to the same extent; and while some authorities in applying the doctrine of judicial estoppel have taken cognizance of the presence or absence of such elements, this has been said to be the result of confusing the two doctrines. % * * »
The foundation of the doctrine of judicial estoppel was pointed out in the case of Hatten Realty Co. v. Baylies,
The doctrine of judicial estoppel was applied by this court in the case of Rossi v. Hammons,
The doctrine of judicial estoppel is equally applicable to the case at bar. The parties in the guardianship proceeding and in the instant case are the same; and the questions involved are identical, namely the mental capacity of Ida Grant. Appellant swore, in both her petition for guardianship and in the guardianship proceeding, that Ida Girant was on June 30, 1948, and for two years prior thereto, mentally incompetent. Thereafter, in the lower court, in the instant case appellant proceeded to do an “about face” by testifying that her petition and former testimony were untrue and that Ida Grant was competent on February 9, 1948, the date the deed in question was executed. Appellant will not be allowed to take such a contrary position to the prejudice of appellee.
The judgment ol the lower court is affirmed.
