Forensics C

[aenakhan]

Out of all the topics, I also noticed we have to know about blood spatter patterns and dna analysis. I'm new to this, so do both hold a high importance during competition?

[baseo1234]

Out of all the topics, I also noticed we have to know about blood spatter patterns and dna analysis. I'm new to this, so do both hold a high importance during competition?

I believe it does, I have been researching this and blood splatter and dna analysis seems to be a vital part of the competition, especially because it is forensics and is often used in real life situations.

Is there any specifics for identifying any polymers or could it be dealt with broadly?
Sometimes I wonder if this lab event would actually influence one to become an forensic investigator, since one is learning about all the elements of forensics, such as blood splatter, polymers, etc.

[samlan16]

Out of all the topics, I also noticed we have to know about blood spatter patterns and dna analysis. I'm new to this, so do both hold a high importance during competition?

They are standard fare at most tournaments, but I would recommend looking at the test exchange to get an idea of the extent to which you need to study each. Typically, there are a couple of background questions to go with both sections, so it's more than matching.

Is there any specifics for identifying any polymers or could it be dealt with broadly?
Sometimes I wonder if this lab event would actually influence one to become an forensic investigator, since one is learning about all the elements of forensics, such as blood splatter, polymers, etc.

I would recommend starting off with density testing. The national website takes you here, which is a good place to start. You're not allowed to burn plastics for safety reasons, so they typically give you the results instead. Most tournaments will not give you much to do density testing (i.e. water and alcohol; you might be able to make a NaCl solution), so you will need to find some identifiers for each plastic via qualitative observation.

[Sciolapedia]

When identifying plastics, what do we do if they don't give us certain solutions like vegetable oil, isopropyl alcohol, 10% NaCl, etc

[samlan16]

When identifying plastics, what do we do if they don't give us certain solutions like vegetable oil, isopropyl alcohol, 10% NaCl, etc

They should give you burn tests, but if you don't, use one of the compounds given (preferably NaCl), and make your own solution to do testing. This can technically be done with any compound they give you, but you will already have NaCl results.

[Sciolapedia]

When identifying plastics, what do we do if they don't give us certain solutions like vegetable oil, isopropyl alcohol, 10% NaCl, etc

They should give you burn tests, but if you don't, use one of the compounds given (preferably NaCl), and make your own solution to do testing. This can technically be done with any compound they give you, but you will already have NaCl results.

Have you guys ever had a time when you have not received one of the solutions necessary to complete your flow chart? In general, though, what methods do you use to identify plastics?

[iwonder]

When identifying plastics, what do we do if they don't give us certain solutions like vegetable oil, isopropyl alcohol, 10% NaCl, etc

They should give you burn tests, but if you don't, use one of the compounds given (preferably NaCl), and make your own solution to do testing. This can technically be done with any compound they give you, but you will already have NaCl results.

Have you guys ever had a time when you have not received one of the solutions necessary to complete your flow chart? In general, though, what methods do you use to identify plastics?

I'd avoid using the given compounds to do solution testing personally. You can't measure them very accurately and you're usually only given a small amount.

I generally use density tests, I think I was only ever given burn data at one contest... I also never made a flowchart for plastic testing since I found the density solutions given at each contest varied a lot. I found it was easier to list a lot of densities of solutions and the densities of plastics, and make it up as I went along.

[Sciolapedia]

Did they give you the densities of the liquids?

Also, for the entomology, can you guys post exact times correlated with the arrival of the insects. Like I know that blow flies come first, etc, but I could never find how long this meant the person has been dead.

[catroll]

Hi, I have two quick questions about Forensics. To clarify, only POWDERS will be given in the competition to identify, and not metals or liquids?
And also, would a flow chart or regular chart be easier to identify powders?
thanks!

[samlan16]

Hi, I have two quick questions about Forensics. To clarify, only POWDERS will be given in the competition to identify, and not metals or liquids?
And also, would a flow chart or regular chart be easier to identify powders?
thanks!

No metals or liquids. Welcome to C Division.

As for the chart, do whichever you are more comfortable with. I personally have been doing Crime Busters/ Forensics for long enough that neither give me an advantage, but having a normal chart is helpful for my partner.