On Call: Case Files from a Career in Homicide | What Every Investigator Should Know

by Justin Bocock

Go on call with a homicide detective. Work through thirteen real homicide cases, interviewing witnesses, identifying evidence, and using current technology to identify suspects and ultimately solve a murder. Each case focuses on aspects of the criminal justice system ranging from writing search warrants, to interpreting autopsy reports, to preparing for a complex criminal trial. Experience the stories of the victims and their families as they pursue justice. Each case is broken down in detail, from the detective that actually worked the investigation. You learn the facts of the case as the detective learned the facts of the case. You are on the inside of the homicide investigation, following the facts and evidence to a logical conclusion. No homicide case is cut and dry, these cases are not always what they seem, and there is always a surprise.

On Inside Homicide Investigations is a manual for Homicide Detectives. There is guidance on creating and presenting photo lineups, direction on using the proper verbiage regarding firearms terminology, and advice on dealing with legal challenges like dying declarations, hearsay, and justification of the use of deadly force. Whether you’re a true crime enthusiast, a writer, or an aspiring homicide detective, each case study offers lessons learned and real world skills that will prepare you to be an experienced and well versed homicide investigator.

303 pages, Kindle Edition

Published September 23, 2025

Reviews

[Jill Rey · Rating 5 out of 5]

In an era of true crime enthusiasts, author Justin Bocock highlights true case files from the perspective of a seasoned homicide detective. Taking readers from start to finish, “On Call” relives thirteen of Bocock’s cases.

Bocock professes he always wanted to be a violent crimes detective, working his way through robbery he tested into the Homicide Unit in 2012. As a homicide detective he was involved in more than 140 suspicious death and homicide investigations. Bringing this knowledge to the page, Bocock educates readers on the intricacies of law enforcement and the emotional toll these cases take.

It all begins with a 911 call, as most cases do, but as Bocock relives each of these 13 cases readers glean an entirely new perspective and appreciation for the work each member of the department puts in to solving these cases. As readers ride along with Bocock, the level of death, emotions, and the trauma surrounding those in Bocock’s line of work are immense. Through each case we are introduced to new facets of police work and the intricacies of the law. Step by step, each case gives readers a glimpse into the life of Mesa’s finest.

One detail we quickly learn through reading Bocock’s story is that all detectives inherit a cold-case book when they are welcomed to the job. In Bocock’s case he received the notes and cases from the retired detective who he replaced. But what many readers may not know is that many local police department’s websites include sections dedicated to cold-case homicides. These sections of the website allow citizens to provide information that may be helpful in solving the case. This information is shared with readers as Bocock runs us through the process of solving one of his own inherited cold cases. The meticulous detail, various parties involved, and waiting game for results provide enhanced insight into the beginning to end process of crime scene call out to prosecution.

“On Call” takes readers into some of the most memorable cases from Bocock’s own career as a Homicide Detective. From initial 911 call to putting the perpetrator behind bars, this read is a genuine ride along for any true crime lover.

[Mike Pezzelle · Rating 5 out of 5]

Great read which takes the reader inside the mind of a homicide detective. Detailed stories of various homicides in Arizona.