What Drug is the Perfect Murder Weapon?

Did I really just ask that?  You have to believe me, I’m not crazed or vindictive and don’t have a criminal streak in me.  What I am, though, is a fiction writer I write about murder, mayhem and medicine (usually all three mixed together) and that stimulates lots of thoughts about the perfect crime.  In fact, planning the perfect crime has been churning inside my head for a few days now and I just had to blog about it.  So back to that question: What drug would a killer use to create the perfect murder?

Before I answer that, let me take a minute to give a general disclaimer.  DON’T TRY THIS AT HOME WITHOUT SUPERVISION.  Scratch that!!  Simply, DON’T TRY THIS!  My novels are all about what if’s and this is just another one of those “I’m just saying” things.  So, let’s get back to the matter at hand.

If I were to develop a plot around the perfect drug as a murder weapon, what would I use?  There are a number of possibilities, (and some of my murder mystery friends are probably already thinking of a few).  Let’s first narrow down the field.  Anything that would leave telltale trace should be eliminated right away.  Agreed?

For instance, a strong tranquilizer like Valium would leave lots of evidence in the blood.  We have to find a drug that either leaves no metabolite trace or one that is indigenous to the body anyway.  Let’s discuss that first possibility: leaving no metabolite trace.

What is a metabolite anyway?  By definition, it’s a byproduct of the body’s metabolism.  It’s what’s left after the body breaks down a substance into either smaller components or changes it (the drug) into other chemicals.  Like when we eat an egg (made up of protein, carbs and fat), our bodies break down that omelet into components that it can use for fuel and the rest is eliminated.

The same thing happens with drugs.  They’re broken down into metabolites (the breakdown products) and those byproducts circle around in blood and provide a therapeutic (or toxic) effect until we eliminate them (usually through the kidneys).

So what drug leaves no metabolite trace?  The simple answer is NONE.  Nothing came to mind as I wrote this blog and a quick Internet search revealed no new epiphany, except for a couple of fictional drugs concocted by mystery writers with more active imaginations than mine.

And with that we’re left with our second possibility: a drug that may leave behind metabolites, but only ones that are normal to the body.  There are several possibilities, but two come to mind that are excellent.

The first is succinylcholine (SUX for short).  It’s a neuromuscular paralytic drug.  In short, it causes ALL the muscles in the body to be paralyzed.  They simply stop functioning, including those used for breathing.  So without medical help, a person given a dose of SUX will stop breathing and asphyxiate.  That happens in a matter of seconds and certainly less than a minute after a person is injected with the drug.  That’s why it’s used in anesthesia.  It helps doctors get those breathing tubes down the throat easier during surgeries.  It’s a wonderfully effective drug and fast acting, but the bad news is that while the drug is working (causing ALL muscles to stop functioning) the person remains wide awake with no sedative effect.  So it’s an agonizing death for sure.

Why would SUX make a great murder weapon?  Because it metabolizes (gets broken down by the body) almost immediately into the byproducts succinic acid and choline, both of which are normal to the body.  So at autopsy, minutely elevated levels of these chemicals are the only evidence of the crime, and a toxicologist could easily overlook the slightly abnormal blood chemistry.  It would be difficult to prove murder without corroborating evidence linking the actual injection to the perpetrator.

The second drug that could make the perfect murder weapon is potassium chloride.  This drug specifically is used for patients with low levels of potassium in their blood.  And, when dosed, the drug simply is metabolized into potassium and chloride, both of which are normally in the body.  But what about elevated blood levels of these components, you ask?  Good question!  You’re paying attention.

The simple answer is found in the effects of a potassium chloride overdose.  It causes severe heart arrhythmias and mimics a heart attack.  In a matter of minutes, the heart spasms out of control and then simply stops functioning in what’s called SCD (sudden cardiac death).  Now that alone is enough to kill but what about those pesky elevated blood levels of potassium.  No problem, because whenever any muscle tissue is damaged (and the heart is muscle tissue), unusually large amounts of potassium are released into the bloodstream.  So a medical examiner would likely list the cause of death as a fatal heart attack.

But the murderer would have to choose carefully which potassium chloride to use.  It would have to be ONLY the injected kind.  The pills that are available from pharmacy shelves wouldn’t work because of the failsafe system we have in our GI tracts to prevent overdoses from unusually large intakes of oral potassium.  The over the counter supplements would just pass through our gut without being absorbed.  The injectable liquid, however, all goes to provide a therapeutic, or lethal, effect.

So there you have it, a BONUS.  Not one but two great drug choices for the perfect murder.  Is it any wonder that the prison system uses both of these drugs in the trio cocktail mix for lethal injections?  Happy writing as you plot the next perfect crime.

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

About James J. Murray, Fiction Writer

With experience in both pharmaceutical manufacturing and clinical patient management, medications and their impact on one’s quality of life have been my expertise. My secret passion of murder and mayhem, however, is a whole other matter. I’ve always loved reading murder mysteries and thrillers, and longed to weave such tales of my own. Drawing on my clinical expertise as a pharmacist and my infatuation with the lethal effects of drugs, my tales of murder, mayhem and medicine will have you looking over your shoulder and suspicious of anything in your medicine cabinet.
This entry was posted in Drugs Used For Murder and tagged , , , , , , , , , , , , , , , , , , , , , , , . Bookmark the permalink.

62 Responses to What Drug is the Perfect Murder Weapon?

  1. Arlee Bird says:

    Found your site via your comment at linked in. Your web site and blog are both excellent. Congratulations on a job well done from that standpoint.

    This post was fascinating, if not a bit chilling. So far I haven’t written anything about murder or putting anyone to death, but now I see I have a good go to source for information such as this. Seeing the quality of what you do I’m willing to offer you a guest spot on my blog if you’d be interested. I think a lot of my readers would be interested in your books and your blog site. A guest post would be a good way to increase your exposure at bit more. I would presume you have my contact information left from this comment.

    Check out my blog to see what I’ve got going and if you might be interested in my offer.

    Lee
    An A to Z Co-Host

  2. website says:

    Is it alright to insert a portion of this on my weblog if I submit a reference to this webpage?

  3. Mia says:

    Heres a question, I am writing my own murder mystery and was wondering that if a small doe of SUX would allow the victim to still breathe while still paralayzing the muscles? Any help would be great. Thanks.

    • Interesting question and difficult to answer since we all react somewhat differently to drug dosing. But the great thing about being a writer is you can write whatever works in your story, as long as it is believable. Remember fiction is nothing more than a believable lie! Since the respiratory system requires muscle actions to function, more than likely those muscles would also cease to function. And a sub-potent dose would work poorly on ALL the body’s muscles, including respiratory muscles.

  4. I came across your excellent blog by searching for KCI+murder. Yes, I’m also in the killing business. Fictitious characters, that is. Mind if I pick your brain? I think I’ve got the basics on the drug, but how readily available is the effective version? And how to hide the injection mark? Between the toes maybe? I also worry that another drug will have to be administered to get the victim to comply while such a huge dosage (as is needed) is injected. Any thoughts?
    Another drug I am investigating is Fentanyl. How traceable would that be in an autopsy?
    Thanks for sharing your expertise!

    • Injectable KCL is available ONLY by prescription but it is readily available to a medical professional, such as from hospital med carts, etc. Injection marks are a problem these days. The street drug abusers have used about every conceivable hiding place for needle marks on the body. Maybe within a body orifice? Fentanyl is a narcotic and is definitely traceable from a tox screen. Good luck with your writing and research!

  5. Amber Opdahl says:

    I’m a nurse and just wondering; yes you would use injectable form but would have to inject directly into the vein. This would make it difficult to use the inside of an orifice or such unless you were trained in anatomy and medicine. It wouldn’t work, for example, to run up and stab someone in the deltoid. Or neck. When I give KCl, it is usually diluted in a bag of 1 L NS. Theoretically, I could get a hold of a syringe of injectable KCl but my brain screams at me to never EVER push KCl. Guess I would make a bad murderess. 🙂

    • I think I’ll sleep better at night knowing that you’d make a terrible murderer!!🙂

      Yes, KCl should be injected directly into the circulatory system to kill. For many years, my pharmacy practice was intravenous pharmacy, TPN therapy to be exact, and the KCl additive was always calculated twice before administration because of its lethal potential. Thanks for commenting.

    • Hey i want to ask if we use the KCl solution and inject it into the body(not in the vein) then again will it cause death or not….

      • Thanks for reading my blog and for your question. The answer is probably not. KCl injected into a vein works acutely to cause cardiac arrest. Other methods of introduction into the body are more slowly absorbed and may not produce a lethal effect.

  6. pretend killer says:

    I bet a good heroin addict could figure out how to grind up some oral potassium supplements and inject them. Prescription potassium supplements would be easier, since they are more concentrated KCl, but the over-the-counter kind are usually potassium gluconate or citrate. You’d need 5-10 prescription tablets, but more like 80 OTC tabs. The problem would be getting rid of the inactive ingredients that could be traceable. I’d bet there’s a reasonably easy way through the wonderful world of chemistry. I will be sure to look into it further before I murder anyone, lol(?). Where there’s a will, there’s a way.

  7. jake dill says:

    What if you injected KCl underneath the wedding ring where no one would look.

    Or what using Scopolamine. II’m pretty sure that that’s untraceable by the common urine and blood tests. The only way to trace Scopolamine was through a rarely used device which I do not remember the name of

  8. Vincent says:

    Hi, am working out for a crime short film. What about 95% pure KCL lab grade powder which are available in eBay n all ? Is it traceable ?

    • Vincent says:

      And what if it’s not injected in vein or somewhere else ??

      • A lethal dose of KCl could only be introduced in the body via an injection and it has to work fast to cause cardiac arrest, so a venous injection is the best shot (so to speak) at that. A SQ or IM injection would be absorbed slower, as any SQ or IM med injection would, so that would not be as effective a route of administration. All the best with your crime film.

    • Of course, I’m sure you are aware that KCl would have to be injected to be lethal. An oral dose would not work because the GI tract will not absorb more KCl than necessary and certainly not a lethal dose. Just as medical grade KCl would not be traceable, the same could be said for a lethal dose of lab grade KCl, although an injection would probably be even more caustic to the veins. Thanks for asking and good luck on your film.

      • Vincent says:

        Hi,
        Thanks for the reply. Sorry, I got another one question like I said earlier it’s 95% pure(what about 5% remaining) and the character is going to inject it as a solution mixed with water. How to get ride of injection mark and it shouldn’t seems to be murder or suicide at any cause. Is it possible for my story ?? Cos I have one FBI sequence it should end without any doubt any help would be greatful

      • Hmmm. Vincent, those injection marks are tricky – they always are evidence of an injection and there’s no spot on the body that a good ME couldn’t find. But there is a way – after the injection, an efficient murderer would have to disfigure the area of the body in a believable way to disguise the injection site. At least, that’s what I would do if I were writing the murder scene.

  9. Vincent says:

    Thanks

  10. Manoj says:

    Hi,
    I used to write many story stories during my school days. Now I got a competition to prove myself in college best story will be published in academy book for 2 years with photo but it should be more realistic n all possibilities. I thought of taking pure potassium chloride from lab which is multi purpose usage injected as a solution but some people said excess of kcl will be easily traced under forensics lab is it true ?? Please help

    • Not easily traced, but yes KCl injected as a lethal dose can be detected by a good forensics specialist. Potassium is released from muscle whenever a muscle is damaged, such as with a heart attack. Good luck on your project.

      • Manoj says:

        Hi,

        Thanks for your kind reply and wishes. I have planned to make a solution of 100gm kcl lab grade powder with 250ml water. Is 30 ml enough to be lethal ?? How long it will take to die ?? And please tell me how doctors are confirming death by heart attack am not asking for KCL in general ??

      • Manoj says:

        Hi,

        Sorry can you please help me I got only 5 days to submit my story

  11. ijaz ahmad says:

    now I am sure that my mother was murdred by KCL injection 4 years ago by my brother in law who is a doctor for money and valuables. pls let me know ,how can we get evedance of kcl injection from her dead body.Rgds

    • I’m so sorry for your loss. To answer your question, I’m not aware of a test on the remains of your mother that could prove your suspicions. You might talk to a medical examiner to get some advice or possibly consult with a lawyer to discuss some options as to how to proceed. All the best to you.

  12. Ins Ulin says:

    Insuline is also one of the possibilities of a killing substance that is natural in the body. But a medical examiner will also find it or the lowered sugar level.

    • You are so right about Insulin being a good murder weapon. I even included it as an option in a blog I wrote last month about “How to Write a Bloodless Death Scene” See that blog at http://wp.me/p2knuT-oX
      But, as you pointed out, Insulin does leave trace evidence in the body by way of abnormal blood glucose levels and high insulin levels.
      Thanks for your comments – All the best!

  13. Roy says:

    Hi,
    In lethal injection procedure three drugs will be used. I know kcl is the major one but injecting kcl alone won’t it make the victim to die in agony ?? Won’t he/she shout like hell ?? In my story I need a silent untraceable one pls suggest

    • Yes, the victim will die in delightful agony!!🙂
      But if you’re looking for a more human way to kill a character in your story, I would suggest succinylcholine, which I also mentioned in that blog.
      Thanks for reading and commenting. All the best in your writing.

  14. Allan says:

    Great article first of all. I need a little help here, my plot is set in early 1800’s and then Forensics were not the same. I need a way through my character kills without leaving any visible marks on the body and is very easy too as he is a naive. My character wants it to disguise it as a sudden death. I have thought about smothering, does it leave any marks?. Any more ideas…

  15. Anand Kumar says:

    How about overdose of KCL with tea

    • It would be difficult to overdose someone with oral KCL because the human GI tract blocks absorption of lethal does of potassium – it’s a natural defense mechanism and that’s why oral doses of potassium are never (translate to “rarely” “almost impossible”) fatal. And that’s also why oral potassium supplements are readily available over-the-counter, because overdoses are not deadly.

  16. RachelLynn Jordan says:

    How long does it take for KCl to affect the body?

  17. lilly says:

    This is amazing… excellent. It is Exactly what I need for my novel. Good job.

  18. Gina says:

    This is very interesting. Thanks! Being a mystery/sleuth fiction writer, I find myself searching the craziest stuff online: weapon models, controlled substances, news about insurgent forces. Does anyone else ever feel nervous that someone high up is going to become suspicious of their browsing history? I mean, I feel relatively free here in the U.S… but sometimes I think “Oh boy, they’re probably having a field day with my searches over at Homeland Security”😐

    • Ha – Yes, I sometimes wonder if Homeland Security will come knocking on my door. Mystery writers have interesting research histories that may give the authorities pause. But, you have to keep it real, so research away! Thanks for your comments and interest. All the best!

  19. I actually must thank you very much for this article. I am writing a book and needed a good murder weapon that wouldn’t show up in an autopsy. My first thought was potassium chloride and I’m glad to see I was spot on. But I do have a question. Is there a dosage of that particular drug that would kill slowly instead of instantaneously? The basic Idea is psych patients being killed with a mix of Thorazine and a lethal poison, in order to simulate death in their sleep. would this be possible?

    • Thanks, Jordan, for your interest and for your question. Potassium chloride is an acute killer and a less than lethal dose would not build up in the body. It would be metabolized and eliminated before building up. You will probably need to think of another lethal substance that slowly accumulates in the body. I’ve blogged about several poisons that will do that. All the best in writing your book.

  20. Jill says:

    So i’m writing a story where soe kids think their step mom may have killed their dad with potassium chloride and i’ve been researching how easy/hard it is to obtain that drug and i haven’t been able to really find anything (i’m probably just not looking hard enough though lol). So i know you have to have a prescription for it but could it be available online through like Ebay or something or some black market? also what medical conditions would people get prescribed potassium chloride? thanks in advance for your reply

    • Yes, Jillian, only IV potassium chloride is lethal and it requires a doctor’s prescription to obtain, but I guess most anything is available on the black market (maybe not so much on Ebay). Usually only severe potassium depletion requires an infusion of potassium chloride and those are rare. Severe dehydration from excessive sweating or whatever reason may be one situation for its use, and I used lots of potassium chloride in my IV pharmacy practice for intravenous nutrition support in the IV feeding mixes of patients who could not take any nutrition orally or via an enteral tube. Hope this helps!

  21. Congrats, James! This one stirred up a hornet’s nest of interest. Super! Well deserved. Trust sales of your novel, ‘Lethal Medicine’, are booming. A very good read!

  22. Thanks, James! This was an early blog and a fun one to write. It resurfaces occasionally on Twitter.
    “Lethal Medicine” is doing well as an eBook and will be available in paperback next week. For my readers who may be interested in reading my International Thriller/Police Procedural “Lethal Medicine”, it can be ordered from Amazon @ http://www.amazon.com/dp/B013CG7AGU or on non-Kindle formats @ https://www.smashwords.com/books/view/566674.

  23. How about one that can just be used as a sedative for a kidnapping? I’m writing a piece in which a character is injected and kidnapped, held for ransom, and later released, but to avoid revealing the location, they’d need to inject this character a second time before dumping them off somewhere.
    Specifically, the plot requires that the victim wake up extremely groggy at first, just enough so that they can be tricked into signing a contract that is later used to blackmail them after their release. Kind of a “keep quiet or we reveal x”.
    Perhaps some way of being momentarily awakened just enough for that with a second drug that quickly wears off and they fall unconscious again.

    • Sounds interesting. Adrenaline is always good for a quick wake up before giving another sedative. In my second novel that’s coming out in November I do an interesting trick to wake a couple of characters up from a sedated sleep. Can’t wait for you to read that one! Thanks for your comments. All the best!

      • brother says:

        As I sit here writing I am choking down my anger at something I was just made aware of and sought out answers. My sister died a few months ago and had been originally ruled an overdose. It was just revealed to me that the official autopsy results stated that there was only trace. The two are total opposites and have increased what I had already felt was shady and was well, I already felt it was intentional. So Google searches of how in the hell could it be ruled a herion overdose when there was only trace of drugs? Led me here, I had already known there are things that exist that do exactly what post states. My question is, if theses things were added to herion, and the originally ruled an overdose, but results were only a trace of the drug, is there a sufficient cause to get an investigation into this. There are so many factors a well with certain people involved that I am not mention, if it is what I feel, I want justice, for my sister,my family and myself.

      • Thank you for sharing your concerns and the best of luck with your struggles.

  24. Jay says:

    I know this post is very old, but you have two things wrong here. A given body weight releases a given amount of kcl on muscle breakdown due to a heart attack. When you inject the amount needed to kill a person, the total amount per ml of blood increases by a noticible quantity. So game over there. Secondly the vein at site of injection will show signs of kcl unless it is diluted thru iv.

    Succinylcholine will leave a metabolite that is disproportional to normal levels. You can isolate it in the brain in excessive quantities. That is how a doctor was caught in the murder if his physician wife.

    • Excellent forensic/detective work, Jay. And that’s exactly how the killer was caught in one of my stories when KCl was used as the murder weapon. Modern science has to run to keep ahead of the devious mind of killers – and so do murder mystery writers.
      Thanks for your comments. They are always appreciated!

  25. Lizzi Newton says:

    If someone with a heart condition was given either of these drugs orally would they kill them slowly. (In minutes to hours.)

    • The short answer to that, Lizzi, is no. Both of these drugs are given IV, and not orally, and even if the solutions were swallowed the effect would not be the same. And a defective heart makes little difference.
      I know there are oral potassium supplements available without a prescription in a pharmacy, but the body has a mechanism in the GI tract to prevent absorption of any lethal quantity of oral potassium. So again, an oral dose is not lethal, even to a weaker heart.

      • Remya says:

        Sir I would like to ask something after reading all these comments..if we inject inj.kcl into bananas and eat it whether it would be fatal.or it wouldn’t absorbed through GI tract?

      • No, it would not be fatal. Any KCl ingested via the GI tract would be absorbed slowly and some passed through to prevent an overdose. Good question, though. All the best!

  26. Ken says:

    Here is another idea for you, Aconite. Tincture of aconite in a bottle of whisky and it’s done. Extremely tough to trace.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s