On the Usefulness of Blood-Grouping in Medicolegal Cases Involving Blood Relationship

The chances of proving non-paternity, when the type of the falsely accused man is known, were calculated. In New York City the average chances of proving non-paternity by means of all four agglutinogens, A, B, M, and N are approximately one in three. A man of type A++ has less than one chance in ten to prove his innocence, and a man of type B++ has only one chance in seven. Men of the remaining ten types, however, have chances ranging from one in four (O++) up to two in three (AB−+).

The chances of detecting interchange of infants in hospitals by means of the agglutinogens A, B, and M and N are seven in ten.