NEW YORK — The discovery of DNA’s double helix structure 70 years ago opened up a world of new science — and also sparked disputes over who contributed what and who deserves credit.

Franklin was no victim in how the DNA double helix was solved. An overlooked letter and an unpublished news article, both written in 1953, reveal that she was an equal player.

In his 1968 book "The Double Helix," Watson alleged that he saw Franklin's photograph without her knowing and upon first glance he was able to spot DNA's double-helix structure, making it appear ...