Riley Spartz is not an actual Minneapolis-St. Paul television news reporter. But she might as well be.

As many mystery novel readers know, Spartz is the creation of Julie Kramer, a former investigative journalist for WCCO-TV and currently a freelance producer for CBS and NBC. She lives in White Bear Lake.

"Silencing Sam" (Atria, 336 pages, $23.99) is the third Spartz mystery within three years, following "Stalking Susan" and "Missing Mark." The scenes set in the Twin Cities and outstate Minnesota are based on firsthand research. The behind-the-scenes routines and surprises of TV news, while sometimes more dramatic than in real life, resound with credibility. Kramer writes journalism novels with as much insight about the craft as any I have read, and I have read hundreds.

The "Sam" of the title is a Twin Cities newspaper gossip columnist shot to death by one of his many enemies. Solving Sam's murder constitutes one plot line. It intertwines with two other primary plot lines -- the unsolved murder of a beheaded young woman, and lethal violence at a wind farm in southern Minnesota, in the very cattle-raising town where Spartz grew up and her parents still reside.

Spartz's investigation becomes complicated when police decide she is the primary suspect in Sam's death.

Kramer is masterful at hiding the identities of the actual criminals until late in the novel. A few of the plot devices seem forced -- too convenient by half -- but Kramer never descends into outlandishness.

Spartz, age 36, narrates the novel, which means Kramer has needed to learn skillful use of the first-person voice. Spartz is a sympathetic character -- ambitious, self-deprecating, sometimes proud, sometimes mortified by herself. That is to say, she is a complex human being, rather than a one-dimensional cartoonish heroine. Spartz is a widow; her police officer husband died in the line of duty three years earlier. Now in love with another Minneapolis police officer who has moved to Washington, D.C., to work for the Department of Homeland Security, she is struggling with whether to marry him, and whether to bear children before her biological clock strikes midnight.

Given the multitude of law enforcement characters, Kramer might have been tempted to turn the novel into a police procedural, as so many mystery writers do. There are indeed police procedural elements throughout the novel, and they are convincing. But at its foundation the book is a journalism procedural, a choice that distinguishes it from the bulk of mysteries published so far in the 21st century.

"Silencing Sam" works well as a stand-alone novel. It works even better when read third, after "Stalking Susan" (which revolves around a serial killer who targets women of a certain name) and "Missing Mark" (which revolves around a missing-person case). I hope Spartz returns for a fourth novel.

Steve Weinberg collects novels with journalists as protagonists. The collection is publicly available in the University of Missouri Journalism School library.