The Trump administration began with the 15,903 figure, although Trump administration officials later conceded this total was unsubstantiated.
Under pressure from officials in Nevada, who were understandably eager to address the highly controversial claims, a DHS official sent an email that read in part, "We've manually reviewed some of the 15,903 and confirmed 185 are not U.S. Citizens."
That, in and of itself, was a rather remarkable reduction (185 is roughly 1% of 15,903), but according to state officials who scrutinized the administration's list, the 185 people whom DHS "confirmed" to be noncitizens were actually citizens.
In other words, Mullin referenced the 15,903 figure, when the truth proved to be zero.