I'll Be Gone in the Dark Themes
The primary theme of I'll Be Gone in the Dark is justice. Michelle McNamara dedicated herself to finding the truth about the so-called Golden State killer because she wanted his victims to get justice. Her relentless, even "obsessive search"—as the subtitle states—to identify the killer, even though it did not come to fruition during her lifetime, kept attention focused even when law enforcement resources were applied elsewhere.
Another important theme is persistence. Not only McNamara but also her husband, Patton Oswald, stayed the course even after her death. It was a testament to the amount of work she had done and his understanding of her commitment that the book was finished and published. In terms of the earlier investigations as well, the local and state police throughout California also pursued countless leads, some of which McNamara was able to follow up on even when they had to turn to other investigations.
A third key theme is devotion. McNamara died suddenly and her husband had to decide if he was able to continue her work. He chose to continue, in part as a way to honor her legacy. Working with a team of writers and researchers, he completed the book. It not only was published posthumously but also topped the best-seller charts for weeks. Incredibly, only two months after it was published, a suspect was in custody: the police in Sacramento, California arrested a former policeman, Joseph DeAngelo, who has been charged with a dozen murders.