Don’t know if this belongs in the Cafe, but I’m not looking for discussion of the show itself, but facts about forensics. Can they really do all that stuff? Most of it I buy, but last night:
er…
They took a skeletonized skull, and added clay to determine what the person looked like. OK, so far I buy it. But one of the things they noted was that the victim had epicanthic folds which, combined with measurements of the head, led them to the conclusion that he had down’s syndrome.
I thought that epicanthic folds are just skin-deep. Can you really tell from the skull?
You’re in luck that I recently saw a segment about the woman who came up with the series idea, who was an actual detective I believe. The shows are mostly based on real events. The police work got to her, so she left and became a writer/consultant for the show.
Non-expert here. I merely offer this tidbit from the real Las Vegas CSI director, on whom Grissom is based (incidentally, the real guy IS an insect fanatic, and keeps a huge collection of live insects in his home):
He says that the basic science presented in the show is real and accurate, but that the TIME factor is where they’re grossly inaccurate. In his words, “I takes me months, sometimes years to get and interpret the evidence I need. But that’s just television. They have to wrap things up every week in an hour.”
Well, they did something last night that looked pretty fishy to me – they changed the polarization of the light that they were studying a segment of film by, and got more detail out of it. I’m pretty dubious that film records the polarization state of the light that’s striking it.
(They then compuer-triangulated the location of the room based on what they saw outside the window – pretty unlikely that there’s a custom piece of software around that can do that.)
I don’t think they reversed the polarization, just the “polarity”, changing black to white, etc. to make the image easier to intrepret. This is the same transform as between a photograph and its negative. You can do this easily in most image editors, and something that looks quite normal in one view will look alien when you reverse it. They had a faint blur on a light sky and by reversing it so it was on a dark background, they could more easily see the fine detail.
I don’t think it’s strictly triangulation (using multiple vectors to a target to pinpoint the target location), they could easily locate the origin of the picture from the image of the tower. Knowing what face of the tower you’re looking at gives you a direction and scaling the apparent height of the tower to its known height gives you a distance. It’s simple geometry you could do on the back of an envelope.
As far as the OP goes, I had the same question. No help there. Seems farfetched.
While there are certain skeletal (and specifically cranial) indicators of trisomy-21, I have a hard time believing that the epicanthic fold is one of them.
The techniques and equipment used on CSI exist, but it’s a little misleading on the show. The equipment is much, much nicer on the show than what you get in a real lab, everything is much faster, the rooms and laboratories are very spacious, and almost everyone is far more attractive than the scientists I know.
However, I’ll agree with the show on one thing: the lighting in MY lab sucks too…
I thought it was the other way around; the woman doing the reconstruction identified the condition based on the skull and added the folds because she knew they went with the condition. IIRC she also commented something about the ears which also wouldn’t be reflected in the skull.
I think she deduced the condition from the skull and was just explaining to Grissom what she was doing as she went along, rather than making conclusions as she “found” the ears, folds and whatnot.
I can’t speak to the science, but there is at least one really unrealistic aspect to CSI - I have never heard of a forensic investigator questioning suspects and doing other detective duties in the fashion done on CSI
Hollywood can solve just about any murder or crime in less than an hour. They don’t want or need extras to do the investigation work- it makes the star character(s) seem larger and smarter than life. Who would watch more people doing the same work - The stars would be lost in the shuffle if the team was larger.
With all this budget crisis, there is a small amount of smaller staff/more work/less pay truthfulness here.
All the gadgets and techniques are flashy and look good on the screen too or we wouldn’t be mesmerized to sit thru an entire episode.
Just ask Dennis Fung about his
Back to the OP. I work at a private forensics lab. The criminalists back in the lab have a good chuckle about that show. A few points:
Criminalists almost NEVER leave the lab. If they even speak to other humans its over the phone ($125 and hour, thank you very much) and they are speaking to laywers almost exclusively. If they leave the lab to visit the crime scene, it is usually to take some photos.
Analysis of physical evidence is tedious, time consuming work that is done at the request and control of the lawyers who change their minds, put cases on hold, pass cases off to one another and generally make the work of a criminalist about as exciting as a file clerk.
Cases drag on for years. The physical evidence is often either poor and incomplete or so overwhelmingly obvious that all that is left is for the laywers to hash out minute distinctions. The criminalist almost NEVER gets to say ‘Gotcha!’
Criminalists work many cases at the same time and do so alone. No spicy banter. No sexual tension. 15 minutes on this one, an hour on that one, talk to some lawyer for 20 minutes about the other one , ad nauseum. Oh! Time for lunch!
I saw one of the early CSI shows, and was turned off. A cop was accused of killing a motorist at a routine traffic stop. He said he never fired. Did they check for gunpowder residue? Did they check the gun to see if it had been fired? Nope. That would have been to fast.
Yea this is total BS. Also, Grissom seems to second as a pathologist sometimes. The show is totally unrealistic in this regard. Forensic technicians collect and analyze evidence. They don’t question suspects, make arrests, or do autopsies.
Guys, I think the OP wanted to know about the actual scientific techniques used in the show to reveal evidence about the crime, not the character’s interactions. On that note, if the show were totally realistic, it would be tedious and boring, you can’t hold this against it.
Also, in fairness, the show rarely establishes a time line, who’s to say that time didn’t pass inbetween the scenes? But I digress as I believe it to be a moot point.
Forensic scientists aren’t usually generalists, either.
My son had to choose between the biology and the chemistry stream at the outset, and towards the end of the degree programme the units become highly specialised. A specialist in - for instance - blood spatter patterns, will usually only have an elementary knowledge of - say - arson, explosives, ballistics, toxicology, etc.
There’s an excellent (and extremely scathing) government report on how the FBI’s forensic science division works - I’ll see if I can hunt up the link.
Another forensic guy here. What everyone else said.
A coworker of mine found it amusing that some guy on CSI actually promised that he was gonna “take a suspect down”. Not only do we not speak to suspects directly, but at least in our lab, we don’t work for the police, we don’t work for the prosecutor. It is our job to objectively present the evidence, regardless of who would benefit most from the results. That kind of bias is a big no-no.
And as far as timing goes, we tell people that it takes 60 days after receiving evidence to crank out DNA results. And we have the highest average turnover time of any public DNA lab in the country.
But to address the OP specifically, it might have been more reliable to attempt to get a DNA profile from the skull. You can confirm Downs by looking for three alleles at the D21 locus (barring any wacky primer site binding anomalies). A DNA profile would be attempted on skeletonized remains anyway, as it’s the best way to confirm an ID, provided you have adequate family reference samples.
One of my friends is obsessed with CSI, and got me to watch one about two years ago. I don’t remember the exact storyline, but it involved a person who had been run over by a vehicle and killed. They found a chip of the taillight lens at the scene (the guy had been backed over) and were able to immediately track down a specific 1997 Ford Explorer based on that. That was complete BS. Even if they had the right part of the lens, the most they would be able to get out of it would be the model year (because Ford part numbers have a two-digit MY code; “F7” = 97, “E6” = 86, etc.) Since the Exploder is one of the most popular vehicles in the US, there is no possible way they could target a specific car that way. They were talking as if the VIN was on the taillight, which is utterly false. That major inaccuracy really turned me off to the show. I mean, they could have called any Ford parts department and determined in a five minute phone call that the entire premise for the episode was nonsense. Somebody in research wasn’t doing their job.