Mod 5: Body Fluids
main goal of a presumptive test for blood
To indicate the possible presence of blood before confirmatory testing
DNA stands for
Deoxyribonucleic Acid
type of alcohol is found in drinks like beer, wine, and liquor
Inadmissable. They detect stress, not lies—nervous people can trigger false positives
What is one reason polygraph results may not be accepted in court?
To establish a baseline for truthful physiological responses
What is the purpose of control questions in a polygraph test?
part of blood gives most tests a positive result
Hemoglobin
the 4 DNA bases are:
A, T, C, G
Purpose of the nystagmus test
Checks for eye jerking caused by alcohol
What does a polygraph (lie detector) primarily measure?
Physiological responses like heart rate, breathing, blood pressure, and sweat
Can be detected using the Phadebas test
Saliva
3 factors that affect bloodstain patterns
Volume, surface type, angle of impact
Comes only from your mother
mtDNA
Legal BAC limit in Canada is...
0.08%
separates ink into its components using a solvent and a special plate
What is TLC?
During an investigation, a suspect's handwriting seems forced and unnatural. This handwriting sample is...
A requested sample; the suspect may disguise their writing if they know they are being tested
void pattern in blood spatter indicates...
That an object blocked the blood spray, leaving an empty space or "shadow"
Junk DNA is useful in forensics because..
varies between people although it is non-coding DNA.
90% of the alcohol is broken down here
The Liver
detect document tampering
What can we use alternate light sources for?
A non-destructive method can reveal indented writing on paper
Electrostatic Detection Device
Confirmatory test for blood
Teichmann or takayama test
a forensic scientist choose mitochondrial DNA over nuclear DNA in a case because...
mtDNA is useful when nuclear DNA is too degraded or absent (e.g., hair shafts or bones)
The 5 stages of BAC effects leads up to death
Euphoria, Excitement, Confusion, Stupor, Coma/Death
difference between a requested and a non-requested handwriting sample
Requested = written under supervision; Non-requested = existing writing like letters
converts alcohol to acetaldehyde in the liver
What is Alcohol dehydrogenase?