Delay, Deny, Defend: Why Insurance Companies Don’t Pay Claims and What You Can Do About It, the 14-year-old book about health insurance that appears similar to words written on bullet casings fired at UnitedHealthcare CEO Brian Thompson, last week has skyrocketed to the top of Amazon’s nonfiction bestseller list. The book, written by Rutgers Law School professor emeritus Jay Feinman and published in 2010, examines tactics used by health insurers to deny claims. “To improve their profits, insurance companies delay payment of justified claims, deny payment altogether, and defend their actions by forcing claimants to enter litigation,” an excerpt of the book published on the author’s website reads. Feinman’s book was sitting at #4 on the nonfiction bestseller list as of Tuesday night, but reached as high as the second place on the list earlier that day, CNN reported. Investigators have not determined a clear link between the suspected shooter, Luigi Mangione, and the book, but accounts linked to the 26-year-old previously chronicled his struggles with spinal surgery and the medical system on social media. His presumed Goodreads account also included reviews of books about health care, including Back in Control: A Spinal Surgeon’s Roadmap Out of Chronic Pain and Crooked: Outwitting the Back Pain Industry and Getting on the Road to Recovery. Feinman previously told the Daily Beast “no comment” when asked about a possible connection to the book, and hasn’t publicly addressed the shooting since.