Donald G. Ingalls was a former television writer, producer, and director.

Ingalls knew Star Trek creator Gene Roddenberry from their days as officers of the Los Angeles Police Department in the early 1950s. The following decade, Ingalls wrote two episodes for Roddenberry’s Star Trek: The Original Series, the first being the first season’s “The Alternative Factor”. This was followed in the second season by “A Private Little War”, for which he chose to be credited under the pseudonym Jud Crucis. He substituted this name after Roddenberry rewrote the episode, removing many of his overt Vietnam parallels. Jud Crucis was Ingalls’ wordplay on “J[esus] Crucified.”