G.R. No. L-8304; February 11, 1915
ARSENIO CAMO, as judicial administrator of the intestate estate of the deceased Claro Crusillo, plaintiff-appellant, vs. JOSE RIOSA BOYCO, defendant-appellee.

FACTS:
Claro Crusillo died on September 3, 1904, survived by his mother as his sole legitimate heir. His brother, Mariano Crusillo, lived with them but had no right to the inheritance. Arsenio Camo was appointed judicial administrator of Claro’s estate. The administrator discovered that three parcels of land, which were the exclusive property of Claro as evidenced by perfect titles, were advertised for public auction to satisfy a judgment debt of Mariano Crusillo owed to Jose Riosa Boyco. The administrator filed a notice of intervention with the sheriff, asserting ownership, but Boyco filed a bond, and the sheriff proceeded with the sale, adjudicating the properties to Boyco. The administrator then filed a complaint to recover the properties. During trial, it was revealed that Mariano Crusillo had declared the lands for assessment in his name in 1904 (while Claro was alive) and in 1906 (after Claro’s death). The trial court, applying the principle of estoppel, absolved Boyco, ruling that Mariano and his mother were Claro’s sole heirs and that the tax declarations estopped the estate from claiming ownership. The administrator appealed.

ISSUE:
Whether the estate of Claro Crusillo is estopped from claiming ownership over the subject properties, thereby rendering the sale at public auction to Boyco valid.

RULING:
NO. The Supreme Court reversed the trial court’s decision. The Court held that the principle of estoppel under Section 333 of the Code of Civil Procedure does not apply. For estoppel to arise, a party must have intentionally and deliberately led another to believe a particular thing true and to act upon such belief. Here, there was no evidence that Claro Crusillo, his estate, or his administrator made any declaration, act, or omission that intentionally induced Boyco to believe the properties belonged to Mariano. Furthermore, Mariano Crusillo, who made the tax declarations, was not a party to the case, and therefore could not be estopped in this proceeding. The Court also ruled that a declaration for assessment purposes is not proof of ownership, citing prior jurisprudence. The sale of another’s property, based merely on a tax declaration in the debtor’s name, is invalid and cannot convey title. Consequently, the sale to Boyco was declared null and void. Claro Crusillo (represented by his administrator) was declared the lawful owner and entitled to possession. The Court noted that any claim for damages due to the improper execution should be directed against the sheriff, who was not a party to the case.