Detective Badge

Fingerprinting began in 1984

No-one has the same fingerprints, even our own body doesn't. Each finger can be different. 

By 6 months in the womb your fingerprints are developed and shaped which will last a lifetime. They don't change. A scientist proved the validity of fingerprinting for police use by shaving his fingerprints. They grew back in the same pattern. 

The three shapes categorised for identification:- Arches, loops, whorls

But more shapes are listed such as double loop, tented arch, plain loop. 

I did my prints and found my thumb and forefinger are double loop and then they go into plain loop and I think my little finger in a whorl. 

I also did my parents fingerprints and my Dad has a Whorl thumb print and a double loop forefinger, but the rest weren't clear. My mum's thumb is a plain loop and forefinger is a whorl with the rest unclear. Pretty fascinating if genetics play a part in the development of fingerprints. I just need to do my twin brother's. 

https://www.touchngoid.com/8-common-fingerprint-patterns/

https://hastingsmuseum.org/wp-content/uploads/2020/05/Fingerprint-Info-Activities.pdf

https://lozierinstitute.org/dive-deeper/when-and-how-fingerprints-form/

 https://le.ac.uk/dna-fingerprinting/history

https://www.smithsonianmag.com/science-nature/myth-fingerprints-180971640/

https://www.crime-scene-investigator.net/fbiscienceoffingerprints.html

Blood Splatter Analysis.

Three basic types- Passive stain, transfer stain and projected or impact stain

https://www.forensicsciencesimplified.org/blood/principles.html#:~:text=Bloodstains%20are%20classified%20into%20three,and%20projected%20or%20impact%20stains.

Seven categories:- Passive, Projected, impact spatter, cast off, arterial gush or spurt, wipe, transfer. 

https://www.ojp.gov/ncjrs/virtual-library/abstracts/bloodstain-pattern-analysis-recreating-scene-crime#:~:text=There%20are%20seven%20bloodstain%20categories,and%20(7)%20transfer%20bloodstains.

Patterns of the blood spatter are determined by the velocity, direction the blood travelled, angles of impact.  Spines and tails are created in the blood pattern.

https://science.howstuffworks.com/bloodstain-pattern-analysis3.htm

https://www.echemi.com/community/child-got-a-blood-group-when-both-parents-are-o_mjart2205151934_314.html#:~:text=Theoretically%2C%20if%20both%20parents%20are,chance%20of%20an%20A%2B%20child.

o+ is the most dominant and frequently occurring blood type. 

DNA Evidence

Things such as Blood, Skin, Body Fluids, Hair are collected to determine a DNA profile. 

Low level DNA or 'touch DNA' can be collected from places such as bruises where handled roughly. 

Reference samples- biological- are used for side by side comparison. 

Most DNA samples submitted to a laboratory undergo the following process:

1. Extraction is the process of releasing the DNA from the cell.
2. Quantitation is the process of determining how much DNA you have.
3. Amplification is the process of producing multiple copies of the DNA in order to characterize it.
4. Separation is the process of separating amplified DNA product to permit subsequent identification.
5. Analysis & Interpretation is the process of quantitatively and qualitatively comparing DNA evidence samples to known DNA profiles.
6. Quality Assurance is the process of reviewing analyst reports for technical accuracy.

https://www.forensicsciencesimplified.org/dna/how.html

Identical Twin	100%	N/A
Parent / Child Full Sibling	50%	Varies by specific relationship
Grandparent / Grandchild Aunt / Uncle Niece / Nephew Half Sibling	25%	Varies by specific relationship

https://customercare.23andme.com/hc/en-us/articles/212170958-DNA-Relatives-Detecting-Relatives-and-Predicting-Relationships

I'm curious at what the DNA shared percentage would be between an identical brother and niece/nephew. Would it be the same as the father and child sharing 50% or would it be 25% as they're the uncle?

OTHER LINKS

https://whoareyoumadeof.com/blog/how-many-segments-are-in-dna/