When starting a book, he says, the story is not always clear, but Connelly has “a hunch” as to where it is going. The books often reference real-world events, such as the 1992 Los Angeles riots and the September 11 attacks. Events that might seem of minor significance are included in some of the books, because of Connelly’s personal interest in them. For example, City of Bones, in which Detective Bosch investigates the murder of an 11-year-old boy, was written during Connelly's early years as a father of a daughter, and it hit close to home. According to Connelly, he didn't mean to write about the biggest fear of his life; it just came out that way.
Detective Bosch's life usually changes in harmony with Connelly's own life. When Connelly moved 3,000 miles across the country, Bosch's experiences sent him in a new direction in City of Bones, written at that time. According to Connelly, his "real" job is to write about Bosch.
Connelly often changes perspectives between characters in his novels. In Void Moon, Connelly frequently alternates between following protagonist Cassie Black and antagonist Jack Karch. In Fair Warning, Connelly outright changes the overarching perspective of the book on occasion, regularly following protagonist Jack McEvoy in a first-person point of view while occasionally branching away from his story to follow the antagonists in third-person.
變換觀點 (change perspective)，有四種可能，1 + 3 (第一人稱，穿插第三人稱)，或 3 + 1，或 1 + 1，或 3 + 3，
但是，Hope to Die (Lawrence Block)，1 + 1，分別寫 Scudder 和 A.B.，甚至 A.B. 的部份還用斜體字，結果失敗，不能卒讀，讀者只好逢 A.B. 的章節，就跳過不讀，(為什麼會 1 + 1，因為你想通吃，兩個人的內心世界，都要描寫)
1 是心理學的 (psychological) 自述，3 是人類學的 (anthropological) 田野，
意思是說，最難看的 thriller，就是 psychological thriller，
3 + 3，3 + 1，1 + 3，也許會好一點，
所以，書寫和人生，的關鍵在，必須有 3，
Writing style
Grant's prose has been described as "hardboiled" and "commercial" in style. A 2012 interview suggested that many aspects of the Jack Reacher novels were deliberately aimed at maintaining the books' profitability, rather than for literary reasons. For instance, making Jack Reacher have one parent who was French was suggested as being partly because the presence of only American members of Reacher's family would limit the series's appeal in France. The same interview stated that Grant "didn't apologise about the commercial nature" of his fiction.
Hard-boiled 的關鍵在，沒有形容詞，沒有副詞，所有句子，都很簡短，只有主詞，動詞，受詞，比如說，Shit happens，life goes on，比如說，Jack fucks Mary，(twice，of course)，
