The prolific James Patterson, best known as a wildly popular and wealthy mystery novelist, is publishing a work of nonfiction Monday. “All-American Murder’’ is an investigation into the life and crimes of Aaron Hernandez, the star New England Patriots tight who hanged himself in his cell last year after being convicted in 2013 of killing a friend. Film rights have already been sold, and Patterson will talk about the book on a one-hour special episode of “48 Hours” on Jan. 20. Here are five takeaways from the book, which also credits two coauthors.

1. It’s a quick read, competently done, and it does not fundamentally change our thinking about Hernandez as a gifted athlete who fell in with bad people, and then — when he got money and fame — came to think of himself as untouchable by the law. (Not a surprise given how intensely news outlets covered the salacious story as it unfolded.)

2. The publisher says the book is the product of interviews with more than 60 people as well as “on-the-scene reporting.” Some of the original reporting seems obvious, such as the long scenes re-created between Hernandez and Bristol County Sheriff Thomas Hodgson, who ran the jail where Hernandez was kept while waiting for trial. The book also makes extensive use of court testimony and legal documents, and cites plenty of reporting from other sources.


3. Patriots coach Bill Belichick declined to be interviewed for the book.

4. In the end, the authors say that the Hernandez case is still a mystery — why did a wealthy, successful athlete throw it all away by killing his friend? The authors do note briefly in an epilogue that researchers discovered after his death that Hernandez suffered from a severe case of chronic traumatic encephalopathy, or CTE, a brain disease caused by blows to the head, one that athletes in contact sports appear particularly vulnerable to. And although they quote a researcher saying Hernandez’s brain was “totally mangled’’ they positively conclude: “No medical diagnosis could explain all of Aaron’s decisions. . . . No single explanation exists for any of his actions.” (Although researchers have noted that CTE patients can have problems with impulse control and emotional volatility.)


5. While they broke little new ground overall, Patterson and his coauthors dug up this nugget: Aaron Hernandez was “especially fond” of Patterson’s Alex Cross novels.

Mark Arsenault can be reached at mark.arsenault@globe.com.