I’m in the process of writing the second book in my Detective Rosie Young Murder Mystery Series. This one is called The Serial Chemist. The first in the series, Almost Dead, was a great success with a 4.8 out of a 5.0-star rating on Amazon. Click here to read a synopsis or to check out the reviews.

In developing the plot for this new book, I wanted to create an especially difficult case for Detective Young and her partner, Vince Mendez. To do that, I researched websites for tips on how to commit the perfect murder. Fortunately for me as a murder mystery writer, there is much information on the subject, but I found some interesting, yet disturbing, data regarding the clearance rate of modern murders.

A disturbing statistic is that about a third of the murders committed in the United States remain unsolved. Fifty years ago, the clearance rate was over 90% compared to the present-day rate of only 64.1%. Note that the term “clearance rate” does not equal the conviction rate. “Clearing the case” refers to the fact that the investigation resulted in an arrest that went to trial. Since the 1960’s, over 200,000 murders remain unsolved with no arrests.

So, back to my research on committing the perfect murder! What should a writer consider if he or she intends to plot the perfect (unsolvable) murder? The top five considerations to commit the perfect murder are as follows:

• Don’t leave any DNA behind. Tracing DNA to the suspect is the surest way to prove that someone committed a crime, particularly if the DNA is linked to the murder weapon or other very specific incriminating object. The most untraceable crimes are committed in public places—like parks or shopping malls—where lots of different DNA are present.
• Pick a random victim. The easiest murders to solve are those committed by someone close to the victim. A relative, friend, or significant other are always among the first to be considered by the authorities.
• Commit a murder in a different locality than where the murderer lives. The villain should not travel so far as to leave evidence of a trip (such as an airline or hotel reservation) that links to the crime scene, but committing a crime in one’s own locality also often produces connections that make a case easier to solve.
• Don’t allow the villain to be conspicuous. While the general rule is to time a murder in the very early hours of the day when most witnesses are asleep, your murderer should not look out of place on a street or other setting near the crime scene at any time or even be recognized acquiring the murder weapon; and, the murderer should not use a murder weapon that can link the crime back to him or her in any way. Use an unusual weapon that the murderer is not familiar with (common brands only) and the villain should purchase that weapon away from a familiar local.
• Plan an appropriate alibi and getaway. Be sure that the murderer can be connected to an event or to other people at the approximate time of the crime (time of death can usually only be approximate) and make sure your villain uses a method to escape the crime scene that does not provide a definitive description. An easily identifiable vehicle that has a distinct sound, such as a throaty sports car engine, would be something that sticks in the mind of a witness. I’ve read that a bicycle makes an excellent getaway vehicle. It’s not easily identifiable as different from other bikes and it’s relatively silent.

Finally, if your villain commits the perfect crime, you can still enhance the plot by writing in an arrest of your murderer. Remember, when a case goes to trial, the suspect needs to be found guilty beyond a reasonable doubt.

Witnesses are discredited all the time on the witness stand by defense attorneys, and prosecutors often try cases only when the police can deliver “open and shut” cases that will lead to convictions or a plea bargain.

Thoughts? Comments? I’d love to hear them!