He had more than thirty credits as an editor of feature films including Key Largo (1946), Dial M for Murder (1954), and Prizzi's Honor (1985).

Fehr was instrumental in establishing the 1967 "sister city" connection between Los Angeles and Berlin, which he had fled in the 1930s.

[3][6] In 1936, Fehr, who was Jewish,[7] fled the Nazi regime in Germany and moved to United States, travelling first class in April 1936 on the steamship, Washington.

For the next fifteen years Fehr edited dozens of studio films, including A Stolen Life (directed by Curtis Bernhardt and starring Bette Davis, 1946) and Key Largo (directed by John Huston, starring Humphrey Bogart, and introducing Lauren Bacall, 1948).

In his obituary, Allen Eyles notes two 1946 films as representative of Fehr's work, "Many of his films were routine, but A Stolen Life (1946) had the visual intricacy of Bette Davis playing the dual role of two sisters, initially on screen at the same time, and Humoresque (also 1946) presented John Garfield as an outstanding violinist, dubbed by Isaac Stern.

He kept his arms behind his back in close-ups while a member of the studio orchestra perched on each side of him, their hands coming into frame to do the fingering and bowing.

The studio then hired Fehr back, and he went to Europe to supervise foreign-language adaptations of Warner Bros. films in France, Germany, Italy and Spain.

[4][9] Fehr was the co-founder (with fellow refugee Ernest Herman) of the Los Angeles-West Berlin Sister City Committee.