Keith Roysdon is a lifelong writer and is the co-author of three true-crime books, the latest of which is “The Westside Park Murders.” He also writes fiction. The former newspaper reporter and editor has written for CrimeReads about TV’s most unusual investigators, the TV classic “Magnum, P.I.” and beloved mystery series for “juvenile” readers. Roysdon is on Twitter at @keithroysdon