Matter of Rivens, 25 I&N Dec. 623 (BIA Oct. 19, 2011) (DHS bears burden to show that a returning LPR is an applicant for admission under INA 101(a)(13)(C), 8 U.S.C. 1182(a)(13)(C)(2006)); see Matter of Huang, 19 I&N Dec. 749, 754 (BIA 1988) (holding, in the absence of a statutory standard, that no deportation order may be entered unless it is found by clear, unequivocal, and convincing evidence that the facts alleged as grounds for deportation are true); Matter of Kane, 15 I&N Dec. 258, 264 (BIA 1975); see also Landon v. Plasencia, 459 U.S. at 21, 35 (1982) (acknowledging the Boards practice at that time of placing the burden of proof on the Government with respect to returning lawful permanent residents in exclusion proceedings).