DNA evidence analysis is an imperfect science. Provide two reasons why this may be the case

Because DNA analysis requires interpretation which can have errors or mistakes because interpretations are subjective no matter how many people agree with your interpretation even if it is right.

Explanation:

the framers of the constitution insisted that federal judges be nominated instead of elected due to their desire to have judges above the shifting whims of the masses.

the hope, whether achieved or not, was that federal judges would only be beholden to the law and that by not having judges be elected, they would be protected if that law dictated an outcome that ran counter to popular opinion.