Responsa על יבמות 240:15

Q. A went to a village and expected to return the same day. He did not return, and on that day a murdered man was found in the nearby forest. Although the body was unrecognizable as it had been mutilated by dogs, it was identified as A's body for the following reasons: (a) People said that a Jew was murdered; (b) the garments on the dead body were recognized as belonging to A; (c) A's wife identified a mole on the dead body as the one her husband had. May A's wife remarry?
A. Neither a general rumor, nor the finding of one's garments on a dead body, are sufficient to establish the death of an individual. But a woman is believed when she identifies her husband's body through a mole. A's wife may, therefore, remarry.
SOURCES: Pr. 371.