Private: No. 1 Suspect by James Patterson (Private #4)

Since former US Marine Jack Morgan started Private, it has become the world's most successful detective agency. But when his former lover is found murdered in Jack's bed, Jack is instantly the number one suspect.

With his team stretched to breaking point and Jack fighting for his life, he finds himself strong-armed by the mob into recovering $30 million in stolen pharmaceuticals, and Jack realises he is facing his most powerful enemies ever.