Author, lawman, and detective (1855–1928) who was an undercover agent for the fabled Pinkerton Detective Agency. Among other feats, he infiltrated Butch Cassidy’s “Wild Bunch” gang, resulting in the capture of several members. Ink signature, “To my friend, Chas. N. Kessler, with compliments of the author Chas. A. Siringo, Los Angeles, Calif., March 14th 1925,” on an off-white 5.25 x 7.75 page removed from a book. Accompanied by an unsigned biographical booklet. In fine condition. R&R COA.