There are many ways to find a plot for a murder mystery story, including sitting through active court cases involving violent crime, interviewing police officers and detectives, and reviewing news articles about crime and homicide. Developing a relationship with law enforcement can take time but yields authentic, realistic story lines.
When developing the plot for a murder mystery, it is also important to develop the main characters, both good and bad. Selecting a crime scenario that fits the characters and setting helps maintain the plausibility of the story line. Resources such as Writer's Digest, The Wise Sloth, TerribleMinds and Martindale Mysteries give tips from current and former mystery writers to help guide the process of writing a murder mystery.