George Harmon Coxe 
Silent Are the Dead [PDF ebook] 

Flash Casey snaps a photo that holds the key to a corrupt lawyer’s murder Casey shouldn’t have had to go back for more pictures of Stanford Endicott. He was at the court with the other newspaper photographers when the wealthy lawyer was arraigned, and got pictures of him smiling as he put on a hat to hide his bald head. But before Casey can get the negatives developed, a pair of urchins steal his camera case and expose the plates to the sun. At his editor’s orders, Casey visits Endicott’s office for another round of photos. The picture he takes there is altogether more interesting: Stanford Endicott, dead on his office floor.Casey hears a sound in the next room and knows the murderer is close. He gives chase out the front door, and takes a picture just as the killer drives away. Suddenly, Flash Casey has a bigger story than he bargained for.