Serology and FP

loops

characteristic where ridges enter one side and exit on same side

arches

characteristic where ridges enter one side and exit on other side

whorls

consists of circles, more than one loop or a mixture of pattern types

AFIS/AIFIS

Data base used to examine/ compare fingerprint. Automated fingerprint identification system.

8pt/12pt match

Match between an unknown and suspect fingerprint. Must have 8-12 match to be confirmed.

Plastic Print

mud,wax,tar, paint

Visible Print

blood, dirt, ink, grease

latent print

invisible and must be developed and photographed

composite print

combination of 2 or more patterns

3 different categories of prints

plastic, visible, latent

3 different characteristics

arch, loop, whorl

Minutiae points

major features of a fingerprint image and used in the matching of fingerprints.

AFIS

Automated Fingerprint ID system

AFIS pros

Increases Accuracy, faster speed, way to identify suspects with latent fingerprints.

AFIS cons

Incomplete records, inconsistent data transmission, poor data quality.

How many points constitute a fingerprint match?

8-12 points

Different techniques to make a latent print visible

Silver nitrate, dusting, superglue, iodine fuming, ninhydrin

PCR

polymerase chain reaction. millions of copies of a specific sequence of DNA can be made in a few hours

Gel electrophoresis

technique used to seperate DNA fragments according to size.

CODIS

combined DNA index system. DNA database system that contains DNA profiles of individuals contributed by state and federal agencies.

Luminol

water- based solution capable of detecting blood. It changes blood to a pale blue.

White blood cells.

made in bone marrow. Found in blood/ lymph tissue. They have DNA in them.

Red blood cells

Made in bone marrow. Better to study blood of suspects and exclude suspects for blood source.

Plasma

the fluid portion of the blood.

Antibodies

found on surface of red blood cells

Antigens

produced by immune system to attack foreign antigens.

Tails

points in direction of travel.

What is the composition of blood?

Plasma, Red/Whit blood cells, platelets.

Where in serology can we get DNA from?

White cells, sperm cells, bone marrow, tooth pulp, hair roots.

What information can we get from blood?

Blood group, DNA

How does blood typing work?

Blood sample is mixed with A,B, and O blood. If blood clots it reacted and is that blood type

What are the possible results of blood typing?

A RHD+, A RHD-, B RHD+, B RHD-, O RHD+, O RHD-, AB RHD+, AB RHD-

Differences between High, medium, low, and arterial spatter

high- a spray

medium- cast off spray, cluster

low- gravity produced, small drops

arterial- spurts, fairly uniform, shows movement

How does angle and height affect blood spatter appearance?

How big drops are, how far they are spread apart, angle makes a bigger tail.

How do blood drops look on smooth vs rough surfaces

Smooth- splatter

Rough- puddle

How long does it take blood to dry?

3-5 minutes

What colors does blood turn when dry?

Brown/Black