[3][4][5] His work at OCME with Charles Norris, the chief medical examiner, created the foundation for modern medicolegal investigation in the U.S. and Gettler has been described by peers as "the father of forensic toxicology in America.

Prior to his employment with OCME he worked as a clinical chemist at the Bellevue Hospital in Manhattan and taught Biochemistry at the New York University School of Medicine.

An OCME laboratory, where testing was carried out for the presence of the common poisons, was set up on the third floor of the City Morgue building on First Avenue and 29th Street.

A previous chemical test had mistaken copper contamination from the box for thallium leading to Gross's arrest.

He remained interested in toxicology until he died due to a terminal illness approximately ten years after retiring.