recently finished.. 

Although gifted with a superbly logical brain, fifteen-year-old Christopher is autistic and everyday interactions and admonishments have little meaning for him. He lives on patterns, rules, and a diagram kept in his pocket. Then one day, a neighbour's dog, Wellington is killed, so Christopher sets out to solve the murder in the style of Sherlock Holmes... 

However it's not a mystery detective novel. lovely eccentric story filled with humour and pain..

the curious incident of the dog in the night-time by mark haddon