Forensic Science Q&A

[Kyuu Nye 425]

I felt compelled to make this thread after the latest file of DC.

Basically the media creates several misconceptions about forensic science. I will take on the responsibility of correcting those misconceptions to the best of my ability. I have taken forensics courses before, I work in an analytical lab, and I have used many of the techniques you see in the movies and TV and know how they work, why they work, and how the media screwed it up (they always do).

Now, I am not pretending to be a professional, but I do know a lot more than the average person and I do want people to know the real side of the field of forensics. Naturally if anyone else knows anything they can feel free to chime in and I'll link to the answers in this first post.

My area of interest is Molecular Biology, but I have taken Criminalistics courses (the forensic science most commonly seen in TV), just to let everyone know.

So ask whatever you want to know about Forensics, or if you want you can ask me how accurate something was in whatever show or movie (providing that I can watch it to see if it is accurate or not).

[detective1 3]

Cool, just a question why would u say 'the media screwed it up (they always do).', as watch some of Forensic show sometime as it very good idea doing it

Have great day

[Kaitou Kid Legendary Thief 197]

So what really, does a forensics specialist do?

Let's say if someone died mysteriously and family members want an investigation, they do autopsies?

What else do they do?

[Kyuu Nye 425]

Cool, just a question why would u say 'the media screwed it up (they always do).', as watch some of Forensic show sometime as it very good idea doing it

Have great day

The only show that is actually accurate is Forensic Files, and that is because they look at real cases. But the dramatized crime shows that people seem to love, CSI for instance, messes up the science horrible. NCIS is better, but still not perfect.

So what really, does a forensics specialist do?

Let's say if someone died mysteriously and family members want an investigation, they do autopsies?

What else do they do?

No, forensic scientists do not perform autopsies. That responsibility is left up to the ME (Medical Examiner), though depending on the country they may have different names for it or different job specifications. In America however, all forensic autopsies in major cities are performed by a licensed medical doctor whom specializes in autopsies. And generally, though it is not always the case, the autopsy does determine the cause of death. However, in the cases that it doesn't not much can be done, unless there were strange circumstances that could lead to evidence. However anything during that investigation, unless it was murder, would be circumstantial and likely just guess work.

As for what forensic scientists do, it depends on a few things... If we are talking criminalistics, then they perform ballistics tests (including comparative microscopy of the sample bullet), gunshot residue tests, fingerprint analysis, foot print analysis (taking molds, prints or any other method applicable, and comparing to a database of shoes and comparing to suspects shoes looking for identifying marks), sometimes blood splatter analysis and hair analysis (generally microscopic first). Generally forensic scientists in a crime lab do not perform toxicology or DNA testing. They can, but it is not often that they do. That said, MOST of the work in crime labs are DNA and toxicology testing. DNA testing is done in a DNA lab, and is usually a chain of work, so one person will take care of one aspect of the DNA analysis (there are several steps involved). DNA testing is actually one of the more arduous tasks in the lab too, because to isolate and compare DNA can take up to 8 hours of time or more depending on how the final analysis was done. Toxicology is the biggest part though. Toxicology labs get samples from everywhere from crime labs to coroner's offices. It is a requirement that a toxicology report be done on just about everyone upon death. They also do tests on the living for jobs that require it. Their job is to determine what drugs were or are in the system and to determine how much for how long (if possible to determine).

[detective1 3]

I see, thank for help.....

[Detective Rohit 38]

My only concern is that how many people will actually take part in this thread..

Anyways, how can you rate the forensics of CSI (tv series)?

[Kyuu Nye 425]

My only concern is that how many people will actually take part in this thread..

Anyways, how can you rate the forensics of CSI (tv series)?

On a scale of 1-10? 3... They do so much wrong, and so many impossible things. Which is why I prefer NCIS... At least they use proper programs to do analysis. Most of the analysis done in labs today are impossible by eye (a favorite of CSI), it may not look as impressive, but hey, its how it is done. I remember once in particular, a few years ago, they did an array of DNA to ID a suspect, and the main guy looked at the two and said that it was a match.

Now let me put that into some perspective...

This is a DNA array:

Now do you really think that someone could look at two of those and say with any certainty that they were the same? Especially considering that the intensities of the various dots must be measured? Yeah, I don't think I could either.

[Detective Rohit 38]

I thought so....coz i wondered how they just identified it just by Vision.

[aika 23]

I don't know if it is about forensics or so.

let me ask you something if a victim did exercise just before death and was found half a day later

death time of they victim could be inaccurate right.

[Kaitou Kid Legendary Thief 197]

@kyuu: I see. So basically, they are the people who work with evidences and the validity of those evidences?

[Kyuu Nye 425]

I don't know if it is about forensics or so.

let me ask you something if a victim did exercise just before death and was found half a day later

death time of they victim could be inaccurate right.

That would only affect rigor mortis, not time of death estimates. Seeing as how initial time of death is preferably done by core liver temperature these says, exercising wouldn't make a difference. If rigor mortis was the only way to tell, then yes, it would be inaccurate, but not by a huge degree if 12 hours have passed.

@kyuu: I see. So basically, they are the people who work with evidences and the validity of those evidences?

Actually... validity of evidence is determined by the court. The forensic scientists just analyze it.

[Lia. 45]

Do they actually go to the crime scene to collect evidence?

[Lia. 45]

Do they actually go to the crime scene to collect evidence?

[Kyuu Nye 425]

Do they actually go to the crime scene to collect evidence?

A forensic scientist can be on the CSI team, but then they are acting as a crime scene investigator, not a forensic scientist. So, no, not usually.

[dw5chaosfan 8]

I'm planning to take all the classes involved with law, and that includes 2 forensics classes. Guess I can know something about this after a few years, then.

[yungching 24]

Cool! A forensic science thread! :mrgreen: Here's a question: In DC, sometimes Conan asks a police officer to check something for Mouri, and he gets the results within the same day. Is that possible? Or does it depend on what it is he wants checked out?

PS: There are quite a few episodes like that, but I can't remember which ones... If you can't answer my question it doesn't matter

[Kyuu Nye 425]

Cool! A forensic science thread! :mrgreen: Here's a question: In DC, sometimes Conan asks a police officer to check something for Mouri, and he gets the results within the same day. Is that possible? Or does it depend on what it is he wants checked out?

PS: There are quite a few episodes like that, but I can't remember which ones... If you can't answer my question it doesn't matter

It really depends on what. Some things are really easy to check. Fiber comparison, finger prints, and GSR are among the quickest and easiest. Other things like things that require prep (DNA for instance) takes longer. While most forensics tests take under a day, some are not within a feasible time within the scope of the case. DNA for instance can take up to 8 hours or more.

[Lia. 45]

How long does it take for them to run forensic tests to collect evidence?

[Kyuu Nye 425]

How long does it take for them to run forensic tests to collect evidence?

Please elaborate... I need to know what test and collecting evidence usually takes about 1-2 hours.

[yungching 24]

Thanks for the answer. I guess I'll have to find the episodes and watch them again...

[Elizabeth Antoinette 4]

Thank you for this topic. I'm actually considering forensic science at the moment.

[Kyuu Nye 425]

Thank you for this topic. I'm actually considering forensic science at the moment.

You are welcome I'm glad it is appreciated. If you have any questions about the major or areas of forensic science I'll answer those through PM, because it has more to do with the education of Forensic Science than the actual field.

[Elizabeth Antoinette 4]

You are welcome I'm glad it is appreciated. If you have any questions about the major or areas of forensic science I'll answer those through PM, because it has more to do with the education of Forensic Science than the actual field.

Thank you very much!

[detective-db 16]

Uhh... Does this also deals with fingerprints?

So uhh.............. "

Can you identify a fingerprint if it was being covered by an another fingerprint? (just curious)

[Kyuu Nye 425]

Uhh... Does this also deals with fingerprints?

So uhh.............. "

Can you identify a fingerprint if it was being covered by an another fingerprint? (just curious)

Usually not, unless the individual ridges and lines can be isolated and separated. However, it is more likely that the second fingerprint to be left will be the one identified as it is fresher and not disturbed by the first.

The first fingerprint has a high possibility to be smudged which will hinder identification.

AFIS can do a lot, but all it really does is identify points of interest on a fingerprint (aka minutiae) If two fingerprints are superimposed, it makes it difficult to isolate the fingerprints.