CSI stuff:Fact/fiction/both

[PobodY]

You don't get too much drift on your MS?
I know that the biggest problem with our ICP-MS (and ICP-OES too) is drift over time... I guess you can reslope a GC relatively easily.
After that then we have oxides, doubly charged ions, and matrix issues... argon compounds get get in the way of quite a few masses.

To be honest, I'm probably out of date with current foresnic techniques. I haven't studied any since Uni, and the minerals industry is all about throughput... I don't think you'd be doing ~400 samples per day per machine.

However, I do know about instrumental analysis and it's clear that CSI is fiction, but based on reality.
It's like a Dan Brown book... while some of it might be true, most is made up for the sake of entertainment.

 

[Meridian]

Between fifty and a hundred samples a day, roughly.

No drift to speak of. RT is set by the RT lock, and anyway the 6890 is about as robust as any machine ever made. About one every couple of months we have to re-lock it because the RT of the IS has changed from 2.812 (no, I don't know why it wasn't set to 2.800) to 2.821 minutes. The MSD is auto-tuned every morning and as long as the tune worked, the results for any given compound will be the same. The HPLC (which is where the quatitations are done) is recalibrated every run though - UKAS are kinda strict about that sort of thing!

I think you are saying the same as me: the techniques used in CSI are perfectly valid, but the results are shorn of real-world noise, error percentages, context etc.


M

 

[d3adm0nk3y]

My wifes a forensic scientist & has been doing the job for 10 years.
She actually watches CSI, because it gives her a good laugh.
They way they work in labs with hardly any lighting and still manage to find fibres!
It's all too fast, as it takes months for a case to build up!
In real life the Americans are behind in forensic techniques, she used to moan about the factual programs on discovery because it was based on their out dated stuff.
I'll try and get her to post later, when she gets home if you like.

 

[Meridian]

My wifes a forensic scientist & has been doing the job for 10 years.

Met Lab or LGC/FA?

In real life the Americans are behind in forensic techniques, she used to moan about the factual programs on discovery because it was based on their out dated stuff.

I liked the episode of CSI:NY where they needed the RI of some glass and it turns out that their "high-tech" lab doesn't have a GRIM machine!


M

 

[aardvark]

Met Lab or LGC/FA?






I liked the episode of CSI:NY where they needed the RI of some glass and it turns out that their "high-tech" lab doesn't have a GRIM machine!


M

whats a grim machine? - i have never had to find out the refracive index of anything - just interested (i doubt i will ever need to know the RF of anything any time soon!)

 

[Meridian]

whats a grim machine?

Glass Refractive Index Measurement. The machine measures the RI of a sample of glass by comparing it to the RI of a special oil, which is being heated (thus changing the RI). The technique is average at linking fragments to source (because the number of possible answers is limited), but good at eliminating.


M

 

[aardvark]

Glass Refractive Index Measurement. The machine measures the RI of a sample of glass by comparing it to the RI of a special oil, which is being heated (thus changing the RI). The technique is average at linking fragments to source (because the number of possible answers is limited), but good at eliminating.


M

cheers - i don't know why i couldn't figure that out myself form the acronym

 

[d3adm0nk3y]

Met Lab or LGC/FA?

The Met FSS

 

[Sequoia]

i saw one a few weeks ago when they had some diamonds and then some woman had a handheld scanner and it gave a nice rotating molecule and told them it was made of carbon - i almost fell out of my chair! - it should be called a science fiction show.

My personal favourite is when they take a grainy, low-res bit of CCTV footage of a car number plate or something similar, taken from about a mile away, and "enhance" it to give a crystal clear image where you could read the fine print if it was written on the head of a pin. Or when you get a face in a tiny corner of an image, shown as a reflection in a mirror or off a shiny surface like sunglasses, and it magically transforms into a portrait-quality shot that Lord Lichfield would be proud of.

Yeah, right!

 

[aardvark]

My personal favourite is when they take a grainy, low-res bit of CCTV footage of a car number plate or something similar, taken from about a mile away, and "enhance" it to give a crystal clear image where you could read the fine print if it was written on the head of a pin. Or when you get a face in a tiny corner of an image, shown as a reflection in a mirror or off a shiny surface like sunglasses, and it magically transforms into a portrait-quality shot that Lord Lichfield would be proud of.

Yeah, right!

its like magic isn't it? where oh where can i buy one of those infinite depth cameras?

then you get programs like Bones on sky one that don't even try to be realistic - they have a 3D holographic display ala starwars - now thats impressive technology

 

[Sequoia]

its like magic isn't it? where oh where can i buy one of those infinite depth cameras?

then you get programs like Bones on sky one that don't even try to be realistic - they have a 3D holographic display ala starwars - now thats impressive technology

Yeah, but Bones is really (IMHO) a different type of program. It's not (again, IMHO) really intended to be serious. It has that slightly satirical, quip-laden, mildly humourous tongue-in-cheek dialog. It's pure escapism.

CSI, however, doesn't have (much of) that veneer. It takes itself too seriously for that, most of the time.

At the end of the day, they're both just intended to be entertainment, and reading anything more than a thin smear of reality into either is pushing it.

 

[aardvark]

Yeah, but Bones is really (IMHO) a different type of program. It's not (again, IMHO) really intended to be serious. It has that slightly satirical, quip-laden, mildly humourous tongue-in-cheek dialog. It's pure escapism.

CSI, however, doesn't have (much of) that veneer. It takes itself too seriously for that, most of the time.

At the end of the day, they're both just intended to be entertainment, and reading anything more than a thin smear of reality into either is pushing it.

thats true -but its actually more entertaining slagging it off than it is watching it.

 

[luminous]

The close up images from blurry/around corner is very laughable,i mean we wouldn`t need crimewatch if we had that lol.
They also get extremely lucky in cases.Take for example paint transfer from a limited edition sports car that only one bloke owns in usa lol,or spores from a plant that only grows in one council estate in the bronx!.
I watch all the csis and they are entertaining,csi ny had a few decomps on and built a 3d face from a skull using what looked like an ir scanner with a few passes rather than get an artist to do it.That seems believable.

 

[D.P.]

I suspect a lot of it is rubbish made up to make something normally incredibly boring look exciting


Such as the recovery of data from a wiped hard drive by laser reading the exposed platters I saw in one episode


Some things like the "poke a stick in the bullet hole" are I beleive based in reality.

It is said that IBM can recover >80% of the data from a hard disk which has been low-level formatted and refilled with randomized binary data 12 times over, the disk platters smashed in half, and then submerged in water for 24 hours. Aparently the first Simpson's episodes before they were ever aired were nearly lost when the laptop was stolen, dmaged and then thrown off a bridge into a river. The data was recovered successuflly giving us the Simpsons, otherwise it may not have ever aired on TV.


The thing is, a harddisk is a magnetic storage device, and so there is always a magnetic signature which can be read even after formatting and re-writing (and of course formatting in itslef does very little to the actual data). The signal strenght is basically too weak for the hard drive read head to register but specialiased equipment can analyse the magnetic patterns, and then fancy algorithms piece togther the recovered data.

 

[DAVEM]

Been wondering this for a while now; how much of the techiques employed it CSI are real or completely made up. Reffering to things such as the computer simulations, the chemical analyses + the (lack of) time they take, the cut testing on bits of meat etc

I would assume they fall into 3 basic catagories

1) Definately real. Used by forensics teams world over
2) Technically real/available, but eitehr don't work as well as suggested or cost way to much to be common
3) Made up


Anyone know?

There was an article in Scientific American the other week on this. Aparently they are worried that jurries think that CSI is real life, and hence equit people just because there is no 'CSI' type evidence!

 

[Werewolf]

True there are ways to read a wiped and badly damaged disk, so much so that if memory serves one of the approved methods of disposal for military drives is something along the lines of breaking them up then creating a metal fire to actually burn the platters* so nothing is left but ****/ashes.


But I doubt any of the recovery methods involve using a laser in an open room (not a "clean" room - the guy wasn't even wearing a hairnet)
I'm not too up on it, but I doubt you can read magnetic media like a hard drive with an optical solution, and certainly not in a situation where the laser is quite a distance from the platters and the path taken by the beam is exposed to the open air of the (non sterile) room.



*I think they use something like phosphorus to ensure it reaches a high enough tempurature to do the job,

 

[D.P.]

True there are ways to read a wiped and badly damaged disk, so much so that if memory serves one of the approved methods of disposal for military drives is something along the lines of breaking them up then creating a metal fire to actually burn the platters* so nothing is left but ****/ashes.


But I doubt any of the recovery methods involve using a laser in an open room (not a "clean" room - the guy wasn't even wearing a hairnet)
I'm not too up on it, but I doubt you can read magnetic media like a hard drive with an optical solution, and certainly not in a situation where the laser is quite a distance from the platters and the path taken by the beam is exposed to the open air of the (non sterile) room.



*I think they use something like phosphorus to ensure it reaches a high enough tempurature to do the job,

You're right there. I'm surpised CSI would concoct some laser reader gadget, I'm sure a lab as well equiped as CSI's would have a proper clean room etc.