Shecaniah was the son of Jehiel, one of the descendants of Elam. He had first-hand knowledge of the seriousness of the problem of marrying foreign women since his own father was among those who were guilty (Ezra 10:26).1
Several other Shecaniahs are mentioned in Ezra and Nehemiah (see Ezra 8:3, Ezra 8:5; Nehemiah 3:29; Nehemiah 6:18; Nehemiah 12:3), though it is not clear if those references are pointing to this person. The Shecaniah mentioned in Ezra 10:2 was probably among the leading men of the remnant (Ezra 9:1).
2 And Shecaniah the son of Jehiel, of the sons of Elam, addressed Ezra: “We have broken faith with our God and have married foreign women from the peoples of the land, but even now there is hope for Israel in spite of this.