The Carr that they originally blamed lived in Maryland.
Don’t you ever wonder why, for all those years, they didn’t just blame one of the many skilled white artisans that Jefferson employed? After all, that surely would have been better than blaming her six white children on their extended family members, the Carr brothers.
The reason is simple. They didn’t because they couldn’t. Because the children looked so much like Thomas Jefferson!
You’re assuming that persons accusing others are lying, and just picking people to blame to avert blame from Thomas Jefferson. I think they observed conduct in those persons — who shared a family resemblance — that aroused their suspicion.