Frank L. Packard 
The Adventures of Jimmie Dale [EPUB ebook] 

The author of the Jimmie Dale adventures is Frank L. Packard. It began as an intriguing tale of a young man who would break into safes at night to retaliate against the owner and give stolen money to the victims of his crimes. He was discovered by a woman, who then sent him letters with instructions on where to do it. After some time, the same situation started to repeat itself. And when he eventually discovered who she was and fell in love, it seemed like the conclusion was overly sentimental. The main character of the book, Jimmie Dale, also known as the Gray Seal, is an expert safe-cracking vigilante. He patrols the streets preventing criminal acts by thugs, returning stolen property, and defending the underprivileged. The cops and all the thieves he's stopped are after him since he always ends up looking like a criminal, which occurs in New York City. Awesome scenes at Chang Foo's opium den in Chinatown, colorful terminology, and a little amount of repetition.