Since they have a book in the marketing dept, their claims appear not without alterior motive.
The US Justice system allows jury members to benefit from the freedom of the media. It follows then that money is to be made, so they go for reaction, spinning a media storm from sealed jury deliberations. Who can argue?
How much did this trial cost America? Are these peoples' "revelations" of greater value than justice? A belief that someone may be guilty is not the point. In a criminal case the prosecution must prove beyond a reasonable doubt - and 12 people voting aquittal is an indication that the prosecution failed to achieve that.
For a jury member to say, post mortem, that the defendent is guilty of crimes other than those before the court, is to say that the prosecution did not do their job by bringing relevant charges. A conviction based on heresay is not justice. A weak case is not justice.
A conviction that follows the rules of the court is considered "safe" is it is proven that the accused is guilty. A conviction based on inadequate evidence or popular opinion is not a conviction.
Susan Drake, 51, said that during the deliberations, the two jurors who now changed their story "were clear in expressing their feeling he might be guilty but totally clear that the evidence wasn't there and reasonable doubt prevailed." She described the deliberations as "thoughtful and courteous," not intimidating.