AZ - Isabel Mercedes Celis, 6, Tucson, 20 April 2012 - #22

[Lark2]

Can you link this up? I thought all testing of a crime scene, whether in the lab or at the scene itself, was considered "foresnic" testing?

Thanks,

Salem

Here's something, not sure how defintive it is:

Every CSI unit handles the division between field work and lab work differently. What goes on at the crime scene is called crime scene investigation (or crime scene analysis), and what goes on in the laboratory is called forensic science. Not all CSIs are forensic scientists. Some CSIs only work in the field -- they collect the evidence and then pass it to the forensics lab. In this case, the CSI must still possess a good understanding of forensic science in order to recognize the specific value of various types of evidence in the field. But in many cases, these jobs overlap.

http://science.howstuffworks.com/csi.htm

I'v always loosely associated forensics with lab test results, but I think it's reasonable to apply that understanding to tests performed in the field as well.

 

[Madeleine74]

Can you link this up? I thought all testing of a crime scene, whether in the lab or at the scene itself, was considered "foresnic" testing?

Thanks,

Salem

Looking for a type of evidence at a scene and not finding any is not considered forensic testing. People who collect evidence are often different from the people who test evidence. Testing would not be done at a scene because there are strict protocols that need to be followed within a controlled environment for the test to be considered valid.

Links? There are thousands upon thousands, but here's 2 good ones that are pretty comprehensive.

"Forensic analysis does not include the location, identification, collection, or preservation of physical evidence by laboratory or investigative personnel...."


http://www.txdps.state.tx.us/CrimeLaboratory/documents/PEHmanual.pdf

http://www.crime-scene-investigator.net/Phys_Evid_Manual_OR.pdf

 

[prima.facie]

Looking for a type of evidence at a scene and not finding any is not considered forensic testing. People who collect evidence are often different from the people who test evidence. Testing would not be done at a scene because there are strict protocols that need to be followed within a controlled environment for the test to be considered valid.

Links? There are thousands upon thousands, but here's a good one that is pretty comprehensive.

http://www.crime-scene-investigator.net/Phys_Evid_Manual_OR.pdf

as a criminal forensic major...you are 100% correct....
you have crime scene techs who look for and collect evidence and you have lab techs who do the actual analysis in a lab....

and you have to hope they arent like the crime scene techs at the nicole simpson scene....lease:

 

[Lark2]

I think it's safe to say if they didn't find any semen that in and of itself is a forensic test and it clearly say's that thier findings were negative.

It's good to know that their cursory testing in the field didn't indicate any semen. But that's not to say that they haven't found any back at the lab on the items they took into evidence.

 

[Eclipse33]

Thanks! just changed it!

 

[pieper4]

Seems I am a dolt. I accidentally deleted my post... S'ok, though. Might've come off as flouncing.

 

[prima.facie]

Here's something, not sure how defintive it is:

Every CSI unit handles the division between field work and lab work differently. What goes on at the crime scene is called crime scene investigation (or crime scene analysis), and what goes on in the laboratory is called forensic science. Not all CSIs are forensic scientists. Some CSIs only work in the field -- they collect the evidence and then pass it to the forensics lab. In this case, the CSI must still possess a good understanding of forensic science in order to recognize the specific value of various types of evidence in the field. But in many cases, these jobs overlap.

http://science.howstuffworks.com/csi.htm

I'v always loosely associated forensics with lab test results, but I think it's reasonable to apply that understanding to tests performed in the field as well.

there are tests performed in the field such as testing for blood & semen & fingerprints....and if tests show there is some, that evidence is collected and taken to the lab and techs in the lab will do analysis.

even w/ ballistics, you can pick up a casing or bullet and look to see what calibur it is and if you see a gun nearby you can put 1+1 together that the casing came from that gun; however, you cant do any analysis of it there at the scene....that still has to be done in a lab....

drives me NUTS watching CSI (although i do like the show) watching them collect stuff at the scene (always!!), then the same CSIs - carrying GUNS - carry it back to the lab and start working on it right away. yeah, ok! lol

 

[Madeleine74]

There are various tools and chemicals used to look for evidence that may exist and then should be collected at a scene. Certain chemicals will react in specific ways that indicate the presence of blood (whose blood, and whether it's animal or human it doesn't say). Ditto tools used to find areas that may contain latent prints. Ditto for bodily fluids.

The presence of the samples doesn't tell anyone about the identity of the person who deposited the sample. Items have to be collected, preserved, and then tested/analyzed and compared to known standards by a qualified professional to determine if it is an item of evidentiary value relating to the case. Not everything collected will turn into evidence. Many times items are collected and they do not end up being part of the evidence used to litigate the case.

 

[spoiledmom]

Looking for a type of evidence at a scene and not finding any is not considered forensic testing. People who collect evidence are often different from the people who test evidence. Testing would not be done at a scene because there are strict protocols that need to be followed within a controlled environment for the test to be considered valid.

Links? There are thousands upon thousands, but here's 2 good ones that are pretty comprehensive.

"Forensic analysis does not include the location, identification, collection, or preservation of physical evidence by laboratory or investigative personnel...."


http://www.txdps.state.tx.us/CrimeLaboratory/documents/PEHmanual.pdf

http://www.crime-scene-investigator.net/Phys_Evid_Manual_OR.pdf

Thanks for the links! Interesting stuff..

 

[johnQpublic]

IDK I would think that if the have found anything other than blood evidence they would have mentioned it by now in the media and would have an idea of who did it by the dna. JMO had some thoughts on that other blood found in the car and stains on the shower curtain... I think it's within the realm of possibility that when SC had that dog issue or an issue with the dogs that maybe one of the dog's got injured and was bleeding, the shower curtain was handy or old and was used to lay the dog on in a car to get to the vet. Even if it's not the same car used for the vet trip it may have been thrown in the red car just to get it out of the way. .... just a thought

 

[Lark2]

(snipped) drives me NUTS watching CSI (although i do like the show) watching them collect stuff at the scene (always!!), then the same CSIs - carrying GUNS - carry it back to the lab and start working on it right away. yeah, ok! lol

Agree! And then later in the show they pair off for the weekly love interest angle, lol. I guess they've gotta give the stars the screen time.

 

[spoiledmom]

IDK I would think that if the have found anything other than blood evidence they would have mentioned it by now in the media and would have an idea of who did it by the dna. JMO had some thoughts on that other blood found in the car and stains on the shower curtain... I think it's within the realm of possibility that when SC had that dog issue or an issue with the dogs that maybe one of the dog's got injured and was bleeding, the shower curtain was handy or old and was used to lay the dog on in a car to get to the vet. Even if it's not the same car used for the vet trip it may have been thrown in the red car just to get it out of the way. .... just a thought

I'm not sure if they would let us know whose blood or semen was found (if any) until after all their ducks are in a row and an arrest has been made. They had known who the suspect was in the Sierra LaMar case for almost two months based on forensic evidence, and we just found this out last week. They had the suspect under watch the whole time in hopes that he would lead them to her body, but he never did. They worried about public safety and decided they didn't want to put off the arrest any longer. They could be doing the same thing in this case. (I hope).

 

[Madeleine74]

I never watch the CSI or NCIS or any of those shows. Real life doesn't resemble that in the least. It's amazing how many people think cases should be solved in 42 minutes because geez they manage to do it on that there yar TV show, goshdernit!

 

[Madeleine74]

I'm not sure if they would let us know whose blood or semen was found (if any) until after all their ducks are in a row and an arrest has been made.

They would not disclose this information. Why do anything to jeopardize the legal case? Successful prosecution of a case is the #1 goal. LE will do everything they can to preserve the case for the DA.

They may say something at a time of arrest that indicates they have a forensic/DNA link, but they're not necessarily going to give many details.

If you follow any other cases you'll notice this is how it tends to play out each and every time. All is not known until a trial.

 

[johnQpublic]

Agree! And then later in the show they pair off for the weekly love interest angle, lol. I guess they've gotta give the stars the screen time.

lol A real good funny about CSI.... all CSI episodes are filmed in California with the exception of fly over shots from thier so called locations very rarely do they film in Nevada, CSI Maimi is the worst faker... they usually film the bay area shots in long beach cali and the CSI office is actually the FAA Federal Credit Union in Hawthorne CA and they never really go into the building because they shoot those shots on sundays when the bank is closed. Good question alot of folks ask is why isnt there a CSI LA if they film it there... Good Question huh... Answer Because it would be against the law to use authentic police vehicles and uniforms in the manner in which the shows are filmed. Other shows that show LA police cars are filmed on closed sets.. CSI actually goes places. .... totally unrelated but funny.

 

[SmoothOperator]

Yes its in the PDF specifically stating that Isabel's room was searched for semen using a light source and that no semen was found to be present. Call it whatever you would like.

 

[spoiledmom]

I personally don't believe that Isabel's disappearance is related to her being sexually abused by her father. However I do believe he is guilty, of what I don't know...JMO.

 

[johnQpublic]

Okay... So we explored NMcD and come to find that he could be somewhat involved or even maybe not at all... Trying again to look into a JM connection... His sister seems to want to throw him under a bus for being involved with drugs... IDK gonna try my best to do a fact finder on him.. and I just wonder if he had any dealings with NMcD... I also don't think at the moment if it did revolve around JM in some way that it was a person who he messed with and not so much him.

 

[kat77]

as a criminal forensic major...you are 100% correct....
you have crime scene techs who look for and collect evidence and you have lab techs who do the actual analysis in a lab....

and you have to hope they arent like the crime scene techs at the nicole simpson scene....lease:

I have a question for you and madeleine74.

In thread #21 we were discussing latent fingerprints. It started with winterrose's post #389 and continued off and on through lark2's post #630.

We were trying to understand what it means for the toy shelf, mirror, and dresser in Isa's room to be processed for latent prints with negative results.

Maybe you have answered this and I missed it, but are there common reasons why frequently used surfaces would show negative results for latent prints?

 

[soyesterday]

Makes total sense. In more cases than not, a six year old would be taken by a pedophile and the reason is for sex.

Even though that fact is probably true, it's so hard to see it typed out.
It's so sad and incredibly sick and i pray to God this didn't happen to this poor baby girl.
God...i just want her to come home safely to her mom.
And i don't think it's gonna happen.