This book was written in the 90s and is probably the definitive book on this celebrated case.
The authors conclude that it is probable that "Colonel" Lindbergh himself was responsible for his child's death.
While it has long been known that the trial of Bruno Hauptman was a farce, with bias shown by the judge, a most likely biased jury, a poor legal representation for the defendant (His lawyer was frequently drunk), and phony evidence, it has never been proposed that Lindbergh himself caused the child's death.
Although Hauptman was found to possess some of the marked ransom money, and may have been guilty of fraud, there was no solid evidence that the was the kidnapper. He denied any participation in the kidnapping right up to his death in the electric chair.
On the other hand, Lindbergh, although a "national hero" for his flight, was known to have had few friends, was awkward in social interactions and was often cruel to others. He is known to have schemed to play "jokes" on others which were bizarre and hurtful, although he thought them funny. Additionally, he was deferred to by police investigators, was never questioned regarding the death and took total control of the investigation. He manipulated numerous people, creating complex and unnecessary scenarios to direct attention away from himself.
He had the opportunity to commit the crime (probably a "joke" that went horribly wrong), and opportunity to wipe away any prints from the child's room. No prints of anyone were found. He also knew exactly which shutter was damaged so entry could be gained through the window. Even more incriminating, hardly anyone outside the family knew they would be staying at that house on that particular night.
This book is fascinating, thoroughly researched and very believable.
The take-away: How the legal system can go so wrong!
No questions for the parents and a conviction and execution of an innocent man!