The Jefferson DNA in the Hemmings family descendants could have come from generations either preceding or after Thomas Jefferson's generation. Thomas Jefferson denied the allegations. Are you calling him a liar?
Heavens no, we all know politicians would never lie about any sexual liaisons they may have been engaged in. But the very detailed records of visitors to Monticello do not support the contentions of either Jefferson’s brother or his nephews were Monticello around the time Sally Heming would have conceived a child. Those same records also indicate that Thomas Jefferson was there around the time she became pregnant. Again, in the records kept at Monticello, the birth of each Heming’s child are duly recorded, but she is the only slave, to give birth at Monticello, in which the name of the father is not recorded. Of the ten slaves Jefferson gave freedom to eight are Heming’s children or blood related to her. None of this is proof that Thomas Jefferson was the father of any Heming child, but it does point to a very strong relationship between the two, that did not normally exist between a slave owner and a slave.