Anne Cassidy writes crime fiction for children

Anne Cassidy's Looking for JJ tells the story of a 10-year-old girl jailed for killing another child, and her subsequent release with a new identity.

Philip Pullman, who wrote the His Dark Materials trilogy, is nominated for The Scarecrow and His Servant.

They are among six books vying for the prize, to be announced on 8 July.

Cassidy said she based Looking for JJ partly on James Bulger's two young killers and on child murderer Mary Bell.

This wasn't an easy book to write because I know that people have strong feelings Anne Cassidy

Bulger, who was two, was beaten to death by two 10-year-old boys near Liverpool in 1993.

Heartbeat by Sharon Creech, Al Capone Does My Shirts by Gennifer Choldenko and The Star of Kazan by Eva Ibbotson are also shortlisted.

Bestseller Millions by Frank Cottrell Boyce, which tells the story of two boys who find a suitcase full of money, completes the list.

The book has been turned into a film by Trainspotting director Danny Boyle.

'Understanding'

Looking for JJ has already won the Booktrust Teenage Prize and was shortlisted for the Whitbread Children's Prize.

"This wasn't an easy book to write because I know that people have strong feelings about such things," Cassidy said.

"When I tell people about this book, they raise their eyebrows. Perhaps they are thinking of the victims.