In my chosen writing genre of crime, there are several authors best-known for their adult novels, who also pen children's books. James Patterson, who is astonishingly prolific (though he collaborates a
lot) has apparently written a
series of adventures set in Middle School. I sat in the Children's section of my local library, and read one of these, which only took a few minutes. It relied a lot on silly names for teachers and amusing illustrations for its humour. Glancing at other titles in the series, they followed the same formula, but Patterson is a very formulaic writer. The writing didn't really sound like his voice, but the technique did.
I love Carl Hiaasen's crime novels, which are set in Florida, and tackle environmental issues as well as having gripping plots featuring malevolent criminals. No one combines violence and humour as well as Hiaasen. He's also written
five stories for young readers, that emphasise his concern for the environment and in which the violent crime is toned down. It's easy to tell that it's his writing voice.
For me, the most surprising crime writer who's widened his readership is Jo Nesbo. His Harry Hole police investigation novels are choked with adult themes—death, torture, drug-taking and sex—Nesbo's protagonist is, by a huge margin, the most dysfunctional detective around. So, I was truly startled to see a boxed set of Doctor Proctor stories in my local charity shop, with his name on the spines.
These stories are based on farting! You wouldn't guess they were written by the same author.