Blood tests showing nonpaternity-conclusive or rebuttable evidence? The Chaplin case revisited

A defendant accused of being the father of an illegitimate child denies responsibility. Blood samples from the child, mother, and alleged father are studied and the results reveal that the alleged father is excluded. What weight, if any, should the court (if a trial is held) or the jury give to the evidence of nonpaternity? Should the evidence be treated as conclusive proof of nonpaternity or should other evidence be admitted in the trial to overcome the nonpaternity evidence? A medical expert might conclude that a controversy exists because of the court's questioned trustworthiness of the paternity blood testing, while a legal expert might conclude that the controversy arises because of burdens of proof. Both conclusions are valid. The Berry v. Chaplin case held in California in 1946 illustrates this circumstance. In refreshing our memories on this case, we can review the problem in light of today's knowledge.