Murder. It’s forever been the stuff of books, movies, poems and plays. Everyone from Shakespeare to Agatha Christie told foul-play murder stories. That’s because, for gruesome reasons, murder cases fascinate people.
I think murder is the great taboo. It’s also the great fear of most people except, maybe, for public speaking. Jerry Seinfeld quipped, “At a funeral, the majority of people would rather be in the casket than giving the eulogy.”
Yes, murder is the ultimate crime. In mystery books and Netflix shows, murder cases are solved and neatly wrapped up in the end. This leaves the reader or audience with the satisfaction of knowing who done it and probably why.
That’s not always the truth in real life. Many murders go unsolved for a long time. Some go cold and are never resolved. Statistics vary according to region, but probably a quarter of murders never get cleared.
Thankfully, most murders are easy to solve. They’re “smoking guns” where the killer and victim knew each other, the killer left a plethora of evidence at the scene or took it with him, witnesses saw the murder take place, or the bad guy confessed to the crime. That’s really all there is to getting caught for committing a murder.
So, why do roughly twenty-five percent of people get away with murder? It’s because they don’t make one of these four fatal mistakes. Let’s look at each in detail and how you can get away with murder.
Leaving Evidence at the Scene
Did you ever hear of Locard’s Exchange Principle? It’s Murder Investigation 101. Dr. Edmond Locard was a pioneer in forensic science. Dr. Locard held that at every crime scene the bad guy would leave evidence behind that would connect them to the offense. Locard summed it up this way:
“Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these, and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value.”
Dr. Locard was absolutely right—most of the time. That quote was from the early 1900s. It was long before the sophistication of DNA profiling and amplifying light to find invisible fingerprints. Today, trace evidence shows up at the micro level, and there’re ingenious inventions used to find it. But… not always.
I’m familiar with a high-profile and unsolved murder case from 2008 where two killers enticed a female realtor to a house and savagely stabbed her to death. It’s a long story. A complicated story. And, so far, they’ve got away with the murder.
The victim was totally innocent. She was set-up as a sacrifice to protect someone else who was a police informant. The police know full well who the killers are—a Mexican man and woman from the Sinaloa drug cartel—but they’ve never been charged. It’s because they left no evidence of their identity at the scene. They’ve also never broken the other three murderer-catching rules.
There’s more to scene evidence than DNA and fingerprints. There are dozens of evidentiary possibilities including hairs, fibers, footwear impressions, chemical signatures, organic compounds, match heads, cigarette butts, expended shell casings, spit chewing gum, a bloody glove or a wallet with the killer’s ID in it. (Yes, that happened.)
Removing Evidence from the Scene
The flip side of Locard’s Exchange Principle is the perpetrator removing evidence from the scene that ties them back to it. This can be just as fatal to the get-away-with-it plan as left-behind evidence. And, it happens all the time.
Going back to the unsolved realtor murder, there’s no doubt the killers left with the victim’s blood on their hands, feet and clothing. This innocent lady was repeatedly shived. The coroner report states her cause of death was exsanguination which is the medical term for bleeding out.
For sure, her killers had blood on them. But, they made a clean escape and would have disposed of their blood-stained clothes. That goes for the knife, as well. Further, the killers did not rob the victim. They didn’t steal her purse, her identification, her bank cards or even the keys to her new BMW parked outside.
The killers also didn’t exchange digital evidence to be traced. They used a disposable or “burner” phone to contact the victim to set up the house showing. It was only activated under a fake name for this one purpose and was never used again. The phone likely went the same place as the bloody clothes and knife.
Being Seen by Witnesses
I once heard a judge say, “There’s nothing more unreliable than an eyewitness.” I’d say that judge was right, at least for human eyewitnesses.
Today’s technology makes it hard not to be seen entering or exiting a murder scene. There’s video surveillance galore. Pretty much everywhere you go in an urban setting, electronic eyes are on you. You’re on CCTV at the gas station, the supermarket, the bank, in libraries, government buildings, transit buses, subways and on the plane.
In bygone lore, the killer often wore a disguise. That might have fooled human surveillance, but it’s hard to trick cameras that record evidence like get-away vehicles with readable plates. It’s also hard to disguise a disguise that can be enlarged on film to reveal uniquely identifiable minute characteristics.
Back to the unsolved realtor slaying again. The killers were seen by two independent witnesses when they met their victim in the driveway outside the show home. One witness gave the police a detailed description of the female suspect and worked with an artist to develop a sketch. It’s an eerie likeness to the Mexican woman who is a prime person-of-interest along with her brother—a high-ranking member of the El Chapo organization.
Unfortunately, there’s just not enough evidence to charge the Mexicans. They left no identifiable trace evidence behind at the crime scene. Whatever evidence they might have taken from the scene hasn’t been found. There was no video captured and the eye-witnesses can’t be one hundred percent positive of visual identity.
There’s also the fourth missing piece to the puzzle.
Confessing to the Murder
Murderers are often convicted because they confessed to the crime. Sometimes, they confess to the police during a structured interrogation. Sometimes, they confess to a police undercover operator or paid agent during a sting operation. Sometimes, their loose lips sink their ship by telling an acquaintance about doing the murder. And sometimes, they’re caught bragging about the murder on electronic surveillance like in a wiretap or through a planted audio listening device—a bug.
Police also arrest and convict murderers after an accomplice turns on them and decides to cooperate with the investigation in exchange for a lesser sentence. Then, there are the revenge situations. The murderer has confessed to an intimate partner who they thought they could trust and couldn’t.
That has yet to happen in the unsolved female realtor murder. There is no doubt—no doubt—that a group of people know what happened in her murder. It’s known, with probable certainty, who the Mexican pair are. It’s also known, with probable certainty, who the real police informant was and who conspired to protect them by offering the innocent victim as a sacrificial slaughter to appease the Sinaloa cartel’s “No-Rat” policy.
This murder case can be solved once someone in the group decides to reveal evidence implicating the killers. That likely won’t be anything in the Locard arena or in the eye-witness region. It’ll be an exposed confession that will solve this case.
Someone will eventually talk. The current problem is that everyone in the conspiracy circle is connected by being blood relatives, being a member of the Hispanic community and being involved in organized crime. Their motive to talk is far outweighed by their motive to stay silent.
Takeaway for The Kill Zone Gang
If you’re a mystery/thriller/crime writer, always consider these four crime detection principles when working your plot. No matter how simple or complex your plot may be, the solution will come down to one or more of these points. If it doesn’t, then your antagonist is going to get away with murder.
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Garry Rodgers is a retired homicide detective and forensic coroner, now an investigative crime writer and successful indie author. Garry also hosts a popular blog at his website DyingWords.net and is a regular contributor to the HuffPost.
Garry Rodgers lives on Vancouver Island in British Columbia at Canada’s west coast. He’s a certified 60-Tonne Marine Captain and spends a lot of time around the saltwater. Follow Garry on Facebook, Twitter and BookBub. He has stuff on Amazon, Kobo and Nook, too.
Fantastic most helpful article!
This is the sort of material which makes TKZ a must-read blog.
Thank you very much!
Nice to hear this, NR. I’m new to The Kill Zone so I’m trying to find my way around and see what interests readers – a least what I can offer. I’ve done variances of this piece before including some on-air talk shows. It always goes over well because most people have never heard the investigation principles put this way.
Your post definitely interested and helped me.
Welcome to TKZ.
Thanks, Jim!
Bookmarking and saving this for my next murder–fictionally speaking. Great organization of complicated details into clear, understandable concepts. Thank you, Garry!
Thanks, Debbie. Are you planning to get away with your next murder or let the chips fall where they may? 🙂
This is very helpful. Despite all my years of reading the TKZ blog, I have not until recently attempted a mystery. It will be set in the early 1900’s so I’m still learning what law enforcement was like at that time and certainly they didn’t have all the tech. Yet the 4 mistakes to avoid that you detail here are most certainly applicable and are great for me to keep in mind as I work on my project.
Great, BK. It’s been a long time since I paged through Sherlock Holmes but I bet it was cutting-edge for the time. So was Agatha Christie but I think she was more into plot and characterization than science.
Fascinating. (To quote Mr. Spock.)
Great information. I’ve made a Word doc from this post. It’s going into my Murder File.
How hard would it be to construct a plot revolving around a suicide where the victim frames another for her “murder”?
Asking for a friend… 🙂
Yes, logical 🙂 Your friend sounds disturbed, Deb. Speaking of a disturbed person who set up her suicide/death by misadventure to look like a homicide – Google “Cindy James”.
That was a *fascinating* read. If it really was suicide, why oh why would she go to all those lengths to make it look like murder? To get back at the ex and all those people who didn’t believe her? What a tortured mind that would take.
Thanks for the tip. Wasn’t exactly a feel good read, but it sure kicked my morning down the road a piece.
🙂
Weird, weird case. I think it was misadventure. But… I have a very knowledgeable colleague who thinks other.
Fantastic info as always, my friend. It may be a bit more plausible for a villain to get away with murder in a rural setting, where CCTV is not everywhere. In upper NH, we have hardly any cameras, minus ATM machines, but neighbors look out for one another. So, don’t let Ms. Nosey Neighbor bag your killer in the midst of stabbing the farmer. 😉 Or do, but she describes the wrong killer.
Thanks, Sue. I’m sure your woodland surveillance system is quite effective. Hey, help me out, buddy. There were four other comments that I was replying to and WP decided to do something funny and post my reply on the wrong comment which is rather embarrassing. So I went into the dashboard to fix it and the comments all disappeared. I’ll go back and see if I can do some sort of online CPR because they probably went to the trash. However, you being much more techie may be able to resuscitate them for me.
Cancel that, Sue – I fixed it 🙂
Hi Garry,
This is terrific information! I’d never heard of Locard’s Exchange Principle. After reading your explanation I understand why it’s fundamental to investigating a homicide. Your four smoking guns that lead to the capture of a detective are very useful. I’ve also make a Word doc of this post to refer to when I need to deal with a murder investigation.
Your account of the two murderers who, so far, have been able to escape justice, reminds me of an observation I read about fictional murder mysteries, namely that if there were forensic evidence (or any of the other three smoking guns you mentioned above) the police would have collared the killer. In a fictional mystery, it can’t be that straight-forward, can it? The sleuth has to find the evidence from clues seemingly unconnected to the crime, to reveal the identity of the killer.
Of course, fiction is not real life 🙂
In your experience as a police investigator, how did you and your colleagues feel about the unsolved cases? Did it depend upon the circumstances? After all, it’s one thing to have two clear suspects like the murder you detailed above, but be unable to come up with enough evidence connecting them to the crime, and another to case where there is no clear suspect. Did you or your colleagues ever work on an unsolved case when you weren’t occupied with a current one?
Thank you for this very informative post!
Great to hear this is useful, Dale. I found that a lot of times truth is stranger than fiction. Some of the cases I was involved in would have been very hard for even the best crime fiction writer to make up.
No investigator likes to be defeated, but that goes with the game. You can only stay with one case for so long because others are always forming in the queue and there are only so many resources to handle them. I’d had one morning where we were working on a recent homicide case that had legs when we were handed two more unrelated murders. Talk about being stretched in different directions.
The stranger-to-stranger murders are the most difficult to solve because there is no nexus to work from. I was involved in the early Highway Of Tears investigation and keep my notebooks because I never know when something is going to break from a new forensic advancement. When DNA genotyping arrived, there were clearances in files – not with charges because the killers were already dead.
I can only imagine how hard it must have been to be juggling multiple cases at once, which must be a regular state of affairs for investigators in many departments and countries. Especially since time is a resource, and, along with personnel, there’s only so much of that to go around.
It’s normal for a murder cop to have 20+ open files. Some are fresh & active. Some are waiting court processing. And, some are so cold you could freeze your fingers flipping through them.
Interesting post. Thanks. As writers, the incredible amount of forensic and technology evidence in the real world is making our jobs much harder if we want to get everything right and realistic on the page. For some readers, it’s making mysteries harder to enjoy because it’s less about people and puzzles and more about what they consider technobabble.
I’m not surprised that historical mysteries and cozies about small towns without a CSI or about magical/psychic characters using other means to solve crimes are a current growth area in mystery.
And thank you for commenting, Marilynn. Yes, forensic sophistication can overshadow the basics of mystery stories like good old plot and interesting characters. Less might be more when it comes to mystery writing.
I’m glad you mentioned magic and psychic characters. I’ve never heard of a real case where psychic information panned out, although I had one where a “psychic” was particularly troublesome. That might make it into a book one day 😉
You’d be surprised at the number of cases which have been helped by psychics. The information is totally Inadmissible, of course, but it’s used more as a tool for cases where the evidence is leading the detectives nowhere, and they need a new direction. Not surprisingly, most detective won’t say a word about this until they retire, then they share that story in a book or nonfiction TV series.
I’m sure psychic information would never be admissible as evidence. But, if information furthers the investigation in a positive way, then it doesn’t matter where it comes from. Thanks, Marilynn!
Garry, this is great information. It gives me a certain amount of confirmation because my cozy WIP features a villain who doesn’t leave any evidence at the scene, isn’t witnessed, and doesn’t share his crime with anyone else. But out of hubris, he takes something belonging to the victim. He thinks there’s no way anyone would even know this item is missing, much less that he has it in his possession. But he didn’t figure on a stubborn, analytical young woman who doesn’t want her friend charged with murder.
Hello protagonist. Good-bye murderer.
I think it’s the trophy collection that does-in some serial killers. They leave nothing at the scene – if it can even be found, don’t have any witnesses, don’t confess but yet they keep a souvenir linking them to the victim. The infamous Robert “Willie” Pickton (the pig farmer from Vancouver who murdered 49 women and fed them to his pigs) got convicted on six counts partly because he had their belongings in his possession. Best for your WIP, Kay!
I can only hope the punishment fit the crime.
Great info. Thanks.
You’re most welcome. Thanks for letting me know, Truant 🙂
Great presentation, Garry, particularly regarding The Locard Exchange Principle which has application beyond criminal apprehension. Thanks!
Thanks, Joe. Good point about evidence transfer extending outside criminal law applications.
Excellent!
Thank you.
Most welcome, Tom. Thanks for leaving a comment!
I’ve heard these principles from my resident advisor, my husband, a 34 year patrol Sargent for the LA County Sheriff and other smaller counties in other states, now retired. However, things have changed since his retirement 14 years ago. He can still advise me on the believability of my character or criminal’s actions and help me with basic weaponry and terminology, but if I want current technology I have to do some research. Thank you for sharing your expertise and knowledge with us. The case studies are fascinating.
Happy to hear they’re helpful. You’re so right about changes, Cecilia. My WIP has a part where I had to research virtual crime scene reconstruction / 3D modeling. The state of the art system is from Faro technologies using next-gen laser mapping called LiDAR for Light Detection and Ranging. It’s a fascinating system that I wish was available in my day.