Jon Cypher is perhaps best known fo his role as Chief Fletcher Daniels on the the police drama Hill Street Blues (he was, in fact , still performing the role when this was made). Notcom 051722.
The title is technically incorrect, as Sister Margaret is a novitiate, not a nun. Notcom 051722.
Altho there seems to be little or no discussion of a possible connection, one of the main plot points of this movie - an inqusitive nun assisting in a crime investigation - would soon serve as the premise for the TV series Father Dowling Mysteries. Admittedly the concept isn't that novel, but what is remarkable, is that it also starred Tom Bosley (as the titular priest) and Michele Greene lookalike Tracy Nelson as the nun. Notcom 051722.