Interesting "Science" on CSI

Feb 22, 1999
Last night, on a rerun of CBS' forensic police science drama (!) CSI, the show's protagonists investigate a multiple-victim stabbing in which only the very tip of the murder weapon was found.

Taking the knife tip to some sort of knife dealing "expert," our heroes watch in fascination as he displays total, utter ignorance of knife technology. (Which makes me wonder -- how much of the "science" on this show is equally flawed?)

The "expert" takes the tip and examines it. I'm paraphrasing, but it went something like this; I may have the exact order wrong, but I'm including everything that struck me as faulty:

"This isn't a knife," he says, "it's symmetrical and ground on both sides in a diamond cross section. This is a dagger. That means it's either carbon steel or stainless steel."

[What would the other choices be in a metal knife, anyway? Aluminum?]

He sprays lemon juice on the tip, which immediately discolors and adopts a blackened patina. "Carbon steel," he pronounces.

He then puts the tip on a piece of paper and uses a ruler to draw lines at the angles of the tip's edges. "Daggers are seldom more than an inch at the base," he says, "so we can estimate the length this way."

So far nothing seems that unrealistic, right?

Well, our "expert" determines that this carbon steel dagger has a five-inch blade. He then goes to his knife case -- which bears several knives, seen quickly, among them a Hibben piece, if I remember correctly -- and immediately pulls out the only five inch dagger in the world: A stainless steel Rigid boot knife.

"That's the one," he says with utter finality.

So what have we learned from CSI?

1. Daggers aren't knives.
2. What makes daggers unique and different from knives is that they're either carbon steel or stainless steel.
3. Lemon juice discolors a carbon steel blade immediately, instantaneously on contact.
3. The only five-inch dagger in the world is Rigid's boot knife, and it must be made of carbon steel, even though the box says otherwise.
4. Rigid's boot knife (excuse me, dagger) is so common, being the only five-inch dagger in the world, that any knife seller has one on hand.

Granted, these are small things -- and there was no obvious anti-knife bias in the episode, no rolled eys and comments of, "Why can people just buy these dreadful things without a permit?" Still, what bothered me was that this one little segment was deeply flawed in its supposedly scientific reasoning, and on a show that is devoted to forensic science, somebody's really, really not doing their homework.

Makes you wonder why anyone ever believes a thing they see on TV, but there you have it...

Anyway, I'm off to buy a Rigid boot knife.


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You getting carbon or stainless?

I'd prefer the Gil Hibben "Nuclear Holocaust" with its 12 tips. That way when they all break off inside my victim, the coroner will think there were 12 assailants.


Good catch Razor. I don't watch much TV, but this is one of my favorite shows. This episode is a repeat.

You've jogged my memory of it, but I think you glossed over the biggest faux pas on the show - how can you possibly get the blade LENGTH from a 1/4" tip of a dagger???!!! Most daggers that I've seen do not have a continuous angle from hilt to point (that would be like a triangle blade) - the point angles out to the blade width, and then the blade edges continue in parallel straight back to the hilt. So, using the tip angle could potentially estimate that the blade is x inches wide, but the blade could be 4" or 8" long, at that same width - how could you possibly know that ????

It kind of ruined that episode for me, this kind of junk science. Writers are just not doing their homework. I guess if they did research like Tom Clancy, they wouldn't be able to put out a show once a week, but it still sours me. Everyone has their field of knowledge that they key on when it comes to TV & movies - for me it's cars, motorcycles, guns, knives. Hard for them to slip any inconsistencies by me. For others it may be military stuff, or medical, or police procedure, whatever.
You're right; it didn't even occur to me as I watched the guy use a ruler to trace the blade shape on paper, but it's obvious looking at the photo of the blade in question that the angle changes for quite some distance and then settles into a straight line.

"Junk science" is right. Though I will say the show itself is well-acted and edited. The star, William Petersen, has had an interesting career, appearing in everything from Manhunter (the movie version of Thomas Harris' first "Hannibal" book, Red Dragon) to Young Guns II to the miniseries based on Peter Benchley's Beast (which, as giant-squid-eating-people movies go, was pretty good).
Can Rev. Razoredj get an Amen from the choir?

The folks you need to complain to are at CBS.
I watch CSI too, but I give it a HUGE grain of salt when it comes to the realism of the techniques. I do like how the CSI's have to use their brains rather than their guns...most of the time. Too bad a real forensics job isn't that interesting. Though if it allowed me to carry, it might be worth the monotony.

If some of the analyses only took the few seconds to run (GC, AA, or MS come to mind), I'd be out of a job! I'm sure that the forensics techniques are "altered" for the show to avoid giving away information. I've noticed some glaring errors in DNA testing and analytical chemistry techniques.

"Reverend Razoredj." I like the sound of that.
It's soooo obvious, had the knife "expert" simply placed the broken tip under a Pyramid he would have clearly seen that the killer was indeed a surviving alien from "Independance Day" bent on destroying mankind and striking a fatal blow to the knife industry in the process.:D

by the way what is carbon and or stainless steel?? if such a material did exist I might have to replace my old flint knife. :D
Razor, I have seen this episode before. I was thinking the same as you. I love CSI but sometimes they do get carried away. They showed some cheesy looking knives on that one didn't they :D
The folks who market Rigid ought to be pleased at the impressive body count their boot knife racked up, too.
I've never watched CSI but I can tell you from seeing other shows like ER and other medicine oriented shows (my area of work) that they are an absolute joke. They've usually taken things so far as to assume that all viewers are morons and make no attempt at development other than a quasi-soap opera character development.

What's worse than the 'junk science' you see portrayed in these shows is that they don't have an "Idiot Warning" like they require with other shows. I mean, you see that on Guiness or similar shows all the time... "These stunts are performed by TRAINNEEDD professionals and should not be attempted by viewers!" :rolleyes: Seems to me that these pseudo-dramas should have a similar warning... "Please understand that this show is a work of FFIICCTTIONN and bears no weight in any 'real' situation whatsoever so viewers should NOT make decisions based on information seen here."

Sounds ridiculous, I know, but if you listen to conversations in the community you can sometimes hear someone quoting something they saw on TV (Fiction!) as a true statement... It's hilarious until the reality sinks in and then it is quite sad. I've even had patients ask me about certain things they've seen on TV which begs the question "Would they have gone ahead and DONE that if they didn't ask someone?" :eek:

I have reduced my TV viewing significantly and try to stick with Documentaries, Nature Stuff, or just good 'ol Sit-Coms! The other stuff is just nauseatingly superficial.

Quasi-Rant mode 'OFF'

Hey guys
I have been a police Officer for over 16 years . The crime scene guys at my dept go in take a few pics spread the whizzo dust around and then go have coffee. I would like to see them make a weekly show about that . Actually the crime scene guys work really hard on the big stuff but it is not as glamorous as CSI.
I would love to have that "expert" on the stand for cross eximination - what a hoot! Get him to look at the blade tip, draw his pretty picture, show it to jury & explain his certainty of blade length . . . then start showing them other dagger-tipped blades: Gerber Guardian vs. Mark II, Boker Smatchet, CS para-edge, maybe a sword to boot. Good fun! :rolleyes:
TV is TV .. I noticed that to . This is not a knife its a dagger hahahha

Ok I can live with it. Still like this show . Its interesting !

Lots of non interesting stuff on now days. To many survivor clones ect.

They have a few new shows that are simular comming out also.
Thanks for clearing that up for me Razor! I never knew about the carbon/stainless issue... :)

E-mail this to CBS: maybe you'll be a correspondent on their next knife episode!
Gentlemen, and ladies too, my advice to you is, in the words of Edward Abbey, brew your own beer; kick in your Tee Vee; kill your own beef; build your own cabin and piss off the front porch whenever you bloodywell feel like it.

Originally posted by WilliePete
Gentlemen, and ladies too, my advice to you is, in the words of Edward Abbey, brew your own beer; kick in your Tee Vee; kill your own beef; build your own cabin and piss off the front porch whenever you bloodywell feel like it.

After your house catches fire because your television shorted out when you kicked it in, and you stumble out of the burning building blindly (because your home brew has poisoned you), you'll find it difficult to flag down a ride to the hospital (since you'll be seeking treatment for the blocked colon you've gotten after eating all that home-killed beef). And why is this? Because you smell like piss, that's why, having floundered in the puddle festering stagnantly in front of your porch.

Its called ENTERTAINMENT!!!!!
Those who don't know don't question "the stated facts".
Sorta like wrestling, sorta entertainment.
Razoredj, you beat me to this post :) Was watching the episode and as soon as they found that tip lodged in the rib, I was paying full attention to see how they mapped out the deductions. Many techniques they use would actually uncover absolutely nothing, but most tv shows have incorrect facts or science unfortunately.