Forensics: Fingerprints - Loops, Arches, and Whorls

Summary

This video script introduces a three-part series on fingerprint analysis. It begins by defining fingerprints and their unique characteristics, emphasizing that no two are alike. The script outlines the three governing principles of fingerprints: individuality, permanence, and classifiable ridge patterns. It then categorizes fingerprints into primary, secondary, and tertiary classifications, focusing on the eight general patterns: two loops, two arches, and four whorls. The video promises to teach viewers how to identify these patterns, commit them to memory, and distinguish between minutiae in subsequent installments.

Takeaways

• 😀 The video introduces a double loop whirl fingerprint and explains there are eight general fingerprint patterns.
• 📚 The video is the first part of a three-part series, teaching fingerprint identification, classification, and minutiae comprehension.
• 🔍 There are three governing principles of fingerprints: uniqueness, permanence, and classification based on ridge patterns.
• 🔗 Fingerprints are classified into three main categories: loops, arches, and whorls, with loops being the most common (60%), arches least common (5%), and whorls at 35%.
• 🖐️ Loops are classified as either ulnar loops (towards the pinky) or radial loops (towards the thumb) based on the bone they point to, ulna or radius.
• 🏞️ Arches are simpler patterns, with two subtypes: plain arches (gradual curve) and tented arches (sharp peaks). Arches lack deltas and typelines.
• 🌪️ Whorls include four types: plain whorls, central pocket loop whorls, double loop whorls, and accidental whorls. All whorls have at least two deltas.
• 🔑 Ridge characteristics (minutiae) such as ridge endings, bifurcations, and islands are used for secondary classification.
• 🧠 Tertiary classification involves sweat pore placement, which can be used for more precise fingerprint matching.
• 📊 The second and third videos in the series will cover how to lift fingerprints, identify minutiae, and test comprehension through quizzes and practical examples.

Q & A

What is a double loop whirl fingerprint?

A double loop whirl fingerprint is a specific type of fingerprint pattern characterized by having two deltas and two cores that appear to swirl in a yin-yang fashion.

What are the three governing principles of fingerprints?

The three governing principles of fingerprints are individuality, permanence, and classifiability. Individuality means no two fingerprints are the same, permanence indicates fingerprints remain unchanged from six months after conception until death, and classifiability means fingerprints have ridge patterns that can be systematically classified.

What are the three types of classifications for fingerprints?

The three types of classifications for fingerprints are primary, secondary, and tertiary. Primary classifications include general patterns such as loops, arches, and whorls. Secondary classifications are minutiae or ridge characteristics like ridge endings, lakes, islands, and bifurcations. Tertiary classifications involve sweat pore placements.

What is the difference between an ulnar loop and a radial loop?

An ulnar loop is a fingerprint pattern where the ridges enter and exit towards the pinky finger side, while a radial loop has ridges entering and exiting towards the thumb side.

How can you remember the difference between ulnar and radial loops?

To remember the difference, note that 'ulnar' starts with 'u' and is closer to the pinky finger, which is associated with the ulna bone. 'Radial' is associated with the thumb side, which is on the radius bone of the hand.

What are the characteristics of a plain arch fingerprint?

A plain arch fingerprint is characterized by ridges that enter the pattern area and exit in a gradual, non-curved manner, without any deltas or type lines.

How do you identify a tented arch fingerprint?

A tented arch fingerprint is identified by its sharp, pointed pattern where the ridges enter and exit the pattern area in a dramatic, upward and downward motion, without any deltas or type lines.

What is a plane whirl fingerprint, and how is it distinguished from other whorl patterns?

A plane whirl fingerprint is identified by having at least one ridge pattern that goes around in a full circle and crosses a line drawn between two deltas, then returns on the other side of the line.

What are the features of a central pocket loop whorl fingerprint?

A central pocket loop whorl fingerprint has two deltas and ridge patterns that circle around but do not cross a line drawn between the deltas and return on the other side.

How is an accidental whorl fingerprint defined?

An accidental whorl fingerprint is defined by the presence of two or more different types of patterns within the fingerprint or by not following the rules of other whorl patterns.

What is the significance of deltas in fingerprint classification?

Deltas are significant in fingerprint classification as they help identify the type of pattern. Loops have one delta, arches have none, and whorls have at least two deltas.

Outlines

00:00

👁️‍🗨️ Introduction to Fingerprint Patterns

The video script begins with an introduction to fingerprint analysis, focusing on the unique characteristics of fingerprints. The speaker outlines a three-part series, with the first part detailing the eight general fingerprint patterns. The video promises to teach viewers how to identify these patterns, organize them, and commit them to memory. The second part will cover the lifting of prints and the differences between latent, visible, and plastic prints, while the third part will test the viewers' knowledge with practical examples. The script emphasizes the individuality, permanence, and classifiability of fingerprints, introducing the concepts of primary, secondary, and tertiary classifications within fingerprint analysis.

05:00

🔍 Understanding Loop Fingerprint Patterns

The second paragraph delves into the specifics of loop fingerprints, which are the most common type, making up 60% of all fingerprints. Loops are characterized by ridges that enter from one side of the print and recurve back to the same side. There are two subcategories of loops: ulnar loops, where ridges enter and exit towards the pinky finger, and radial loops, which point towards the thumb. The speaker uses anatomical references to the ulna and radius bones to help viewers remember the difference between the two. The paragraph also explains the presence of a delta and two type lines in loop patterns and provides a practical example of identifying an ulnar loop on a finger.

10:01

🌀 Exploring Arch and Whorl Fingerprint Patterns

Paragraph three continues the discussion on fingerprint patterns, introducing arches and whorls. Arches are simpler, with no deltas or type lines, and are divided into plain arches, which have a gentle slope, and tented arches, which are sharply defined. Whorls, on the other hand, are more complex and must have at least two deltas. The script describes four types of whorls: plain whorls, central pocket loop whorls, double loop whorls, and accidental whorls. Each type is distinguished by the presence of circulating ridge patterns and their interaction with an imaginary line drawn between the two deltas. The paragraph aims to clarify the differences between these patterns and provides guidance on how to identify them.

15:02

📊 Classifying Fingerprint Patterns with Examples

In the fourth paragraph, the speaker provides a visual aid to help viewers classify fingerprint patterns. A table is suggested as a tool for practicing and memorizing the characteristics of loops, arches, and whorls. The percentages of each pattern type are reiterated, with loops being the most prevalent at 60%, followed by whorls at 35%, and arches at 5%. The paragraph reinforces the importance of understanding deltas, with loops having one, arches having none, and whorls having at least two. The speaker also clarifies the direction of ridge patterns in relation to the hand's position when making a print, ensuring that viewers can correctly identify ulnar and radial loops in practical scenarios.

20:02

🎓 Conclusion and Encouragement for Further Learning

The final paragraph serves as a conclusion, urging viewers to take their time in learning and memorizing the fingerprint patterns discussed. The speaker recommends practicing by drawing each pattern by hand to solidify understanding. The script concludes by encouraging viewers to proceed to the second video for a deeper dive into minutiae and to use the third video as a test of their knowledge. The speaker thanks the viewers for their time and attention, promising to see them in the next installment of the series.

Keywords

💡Fingerprint

A fingerprint is the pattern of ridges and valleys on the skin of a person's fingers and thumbs. In the video, fingerprints are the central theme, as they are used for identification purposes. The script explains that fingerprints are unique to each individual and remain unchanged throughout a person's life, making them a reliable biometric identifier.

💡Double Loop Whirl Fingerprint

This refers to a specific type of fingerprint pattern where the ridges form two distinct loops. The video uses this as an example to highlight the complexity and variety of fingerprint patterns. It is one of the eight general patterns discussed, emphasizing the importance of recognizing and differentiating between these patterns in forensic science.

💡FRS (Friction Ridge Skin)

Friction Ridge Skin is the skin on the palms of the hands and soles of the feet that has patterns of ridges and valleys. The video script mentions FRS as the basis for fingerprints, which are specifically the patterns on the fingers. Understanding FRS is crucial for studying fingerprints as it is the physical attribute that allows for the detailed identification of individuals.

💡Minutiae

Minutiae are the specific details or features in a fingerprint, such as ridge endings, bifurcations, dots, and islands. The script explains that these characteristics are essential for fingerprint analysis because they provide the unique identifiers that distinguish one person's prints from another's. The video aims to teach viewers how to recognize and differentiate these features.

💡General Patterns

General patterns refer to the three broad categories of fingerprint patterns: loops, arches, and whorls. The video script discusses that there are eight variations of these patterns, which are fundamental to fingerprint classification. Understanding these patterns is key to the systematic organization and identification of fingerprints.

💡Ulnar Loop

An ulnar loop is a type of fingerprint pattern where the ridges enter and exit towards the pinky finger side of the hand. The video uses the ulnar loop as an example to illustrate how the direction of ridge flow helps in classifying fingerprint patterns. It is one of the two loop patterns discussed in the script, highlighting the need for precise identification in forensic analysis.

💡Radial Loop

A radial loop is characterized by ridges entering and exiting towards the thumb side of the hand. The video script contrasts this with the ulnar loop to demonstrate the importance of direction in fingerprint classification. Recognizing radial loops is essential for accurate fingerprint analysis and matching.

💡Arches

Arches are one of the three general fingerprint patterns, characterized by ridges that rise and fall without recurring or touching. The script mentions two types of arches: plane arches and tented arches. Understanding arch patterns is important as they make up a small percentage of all fingerprints and are thus distinctive.

💡Whorls

Whorls are complex fingerprint patterns characterized by two or more deltas. The video script explains four types of whorls: plain, central pocket loop, double loop, and accidental. Whorls are significant in fingerprint analysis because they are the most intricate and can provide a high level of detail for identification.

💡Tertiary Classification

Tertiary classification refers to the analysis of sweat pore placements in fingerprints. The video script explains that sweat pores can provide additional detail for individualizing fingerprints, increasing the accuracy of matching. This level of classification is crucial for forensic experts when trying to match fingerprints to a specific individual.

💡Delta

A delta is a point in a fingerprint where ridges converge and is a key feature in the classification of whorl patterns. The video script mentions that whorls have at least two deltas, which are used to identify the pattern type. Recognizing deltas is essential for distinguishing between different whorl patterns and for accurate fingerprint analysis.

Highlights

Introduction to fingerprint patterns, specifically the double loop whirl fingerprint.

Overview of the three-part series on fingerprint analysis.

Explanation of the three governing principles of fingerprints: individuality, permanence, and classifiability.

Description of the primary, secondary, and tertiary classifications of fingerprints.

Prevalence of loop patterns in fingerprints, accounting for 60% of all fingerprints.

Definition and characteristics of a loop fingerprint, including the presence of a delta and type lines.

Subcategories of loops: ulnar loops and radial loops, based on the direction of ridge lines.

Memory aid for distinguishing between ulnar and radial loops using the hand's anatomy.

How to identify an ulnar loop fingerprint by the direction of ridge lines towards the pinky finger.

Introduction to arch patterns, which make up 5% of fingerprints and lack deltas and type lines.

Differences between plane arches and tented arches based on the shape and sharpness of the pattern.

Introduction to whorl patterns, which constitute 35% of fingerprints and have at least two deltas.

Criteria for identifying a plain whirl fingerprint based on circulating ridge patterns.

Characteristics of a central pocket loop whirl, including the absence of ridge patterns crossing the delta line.

Identification of a double loop whirl fingerprint by the presence of two core patterns resembling a yin-yang.

Definition of an accidental whorl as a pattern with two or more different types of patterns or one that doesn't fit other categories.

Summary table of fingerprint patterns, including the number of deltas and key features for each type.

Encouragement for viewers to practice drawing fingerprint patterns to aid in memorization.

Conclusion and transition to the next video in the series focusing on minutiae and fingerprint analysis.

Transcripts

this is a fingerprint

but not just any fingerprint oh no no my

friends

this is what you call a double

loop whirl fingerprint

double loop

whirl fingerprint

stick around as you will learn the

difference between

all eight general patterns i will show

you how to organize them

i'll show you how to commit them to

memory and give you some tips and tricks

along the way

all in this first video of this

three part series

in the second video i will show you how

to

lift prints i will show you the

difference

between latent prints visible prints

and plastic prints and

finally i will show you how to tell the

different minutiae

like ridge endings lakes islands

bifurcations that kind of thing

from each other and finally in the third

video

i will give you the chance to test your

knowledge i will show you 20

different fingerprints and give you a

chance to name them correctly

and i'll give you a chance to check your

minushi

comprehension by putting up on your

screen two fingerprints

and giving you the chance to determine

whether or not they

come from the same finger all right

let's get right to it

so first things first what is this frs

well frs or friction ridge skin

that's the the peaks and valleys that

make up the fingers and the palms of

your hands

as well as the soles of your feet

and a fingerprint then is the

frs on the fingers specifically

and there are three governing principles

that govern fingerprints number one

a fingerprint is an individualistic

characteristic in other words no two

fingerprints are the same even between

your

right index finger and your left index

finger for example

even between two identical twins

no two fingerprints are the same

number two a fingerprint remains

unchanged throughout the life of the

person

from six months after conception

all the way until death your

fingerprints stay

the same and the third governing

principle

is that fingerprints have ridge patterns

that can be systematically classified

all right well there are three different

types of classifications

primary secondary and tertiary the

primary classifications are what we call

general patterns we got loops we got

arches

and we got worlds so between

those three there are actually eight

general patterns

we got two loops two different kinds of

arches

and four different kinds of worlds

notice what i have here there there are

six sixty percent of all fingers

in the whole world are loops

are some kind of are one of the two

different kinds of loops

five percent are arches and 35 percent

are worlds the secondary classification

are what we call

minutiae or ridge characteristics

i i see all these different kinds of

lines but i also see little dots

and islands and and lakes bifurcations

those are called ridge characteristics

or minutiae

and third we have tertiary

classifications

and these are what are the sweat

pore placements your your sweat glands

in your fingers and and palms of your

hands

lead to sweat pores and we can actually

individualize or or

with with more certainty we can

associate or or match to a common source

with with more

certainty when we look

at at how close and far away and where

exactly those

sweat pores are so that's tertiary

classification all right so let's

let's do loops and then we'll do arches

uh and then we'll do whirls

what makes a loop a loop well a loop

must have at least one

ridge entering from one side of the

print

recurving and going back the same side

that's what makes a loop a loop

well there are two different kinds

there's two subcategories of loops

if the ridges enter and exit

towards your pinky finger

it's called an ulnar loop

if the ridges enter and exit towards the

thumb

it's called a radial loop so what does

ulnar

and radial mean well these are the two

bones

that lead to your hand so let's just

take a look here

so here we got a skeleton and this

bottom finger here

this is your pinky finger and therefore

this bone is the ulna this is the

ulna and the pinky the ulna is right

above the pinky

this is your thumb this is your right

hand now this is your thumb

and that's the that's the radius

so again here is your pinky

and this is the ulna well how can you

tell ulna from radius how do you

remember

well ulna starts with the letter u and

u is closer to you so that's how you can

kind of remember here's you

and here's and here's the ulna so the

ulna

is always above

the pinky and of course the hand is is

supine

meaning it's facing forward the palm is

facing forward so that's that's

that's how you can tell the two apart

the ulna is above

the pinky now

so so so again if if if you can imagine

now

the um if the ridge then

enters and exits towards the little

finger

it's called the ulnar loop because it's

going towards that

ulna bone and we'll show you this here

in just a second

the pattern area of of the uh um

surround of the surrounding uh ridges

um that that divert those are called

type lines with loops you have

one delta and two

type lines

as well as a core let's take a look here

all right so this is one of one of my

fingers on my

right hand you take a look and use

you you tell me if you can figure out

what this what what we're looking at

here

well i see right off the bat i see here

here is a delta right here

i see ridges

coming in and going out the same

direction

so here is a delta

that's your delta and on both sides

of the delta you have

what we call typelines these type lines

diverge at the delta and they go all the

way around

so how how how again can we tell that

this is

a a loop take any ridge

inside of the pattern there follow it

around

if it goes in and back out

in the same direction that's called a

loop

well since this is a finger from my

right

hand and remember my finger here is

under the microscope

under the dissecting scope so

if you can just i so i want you to take

your right hand

and have your palm facing up so so

you're looking at your your

palm and take a look at your pinky

and imagine your ulnar bone

the ulna just above the pinky

and imagine yourself putting your finger

under the microscope so you're looking

at

um any any fingerprint from your right

hand

since this finger is from the right hand

and these lines these two lines

are pointing where where are they

pointing to are they pointing to

the ulna to the ulnar bone or

to the radius to the ulna or to the

radius

well they're going to your midsection

they're going to the ulna

they're going to your pinky therefore

this

by default is the is an ulnar

loop because those two are

pointing because these two lines come in

and go back out towards your

pinky finger which is associated with

your

with the with the ulna so this is an

ulnar loop

now remember that in this in this

picture that you're seeing here

this is not the pr not a print that you

would normally see

which is because you know when people

touch

a surface you're going to see

the opposite here i'm turning my hand

the other way and just sticking my hand

right on the dissecting scope

looking so just that just so you can so

just so you're not confused

so that's loops my friends those are

loops so we have

ulner loops and we have radial loops

depending on if they open up in

and come back towards the towards the

ulnar bone

or towards the radius

next we have arches we also have two

different kinds of arches

these are a little bit easier here

with arches we we have

plane arches and we have tented arches

well a a plain arch just kind of goes up

and back down nice and easy

whereas tinted arches they are really

really really really really sharp

what else do we know about arches we

know that they have

no deltas and no type lines

so if you remember with pat with loops

there we

have we only have one delta loops have

only one

delta with arches they have

zero they have zero

deltas let's take a look alright

i see here this is a plane

arch and the reason why is because

the lines that come in and out of the

pattern

are pretty gradual definitely

gradual compared to the tented

over here where they come up and down

really really really dramatically they

shoot up and shoot back down

notice there are no deltas there are no

deltas like we just saw

with the loops those are

your arches two different kinds you have

your plane arch

and your tented arch with whirls now

there are four different kinds of worlds

you got plane worlds you have central

pocket loop worlds

you got double loop worlds and you have

accidental

worlds well let's start with let's start

with deltas

how many deltas at least how many deltas

do you have

in worlds there are two different

you have two at least two deltas with

all with all worlds so again

with your um with your loops

loops have one delta arches have

zero deltas and whirls

have at least two deltas

so can you find the deltas here on these

four

different kinds of worlds we got one

here

we got one here let's take a look at the

central pocket loop

the world can you find it

there it is and with a central pocket

loop is

the second one's usually a little bit

hard to find

there it is and even with double loops

you have

you have you got two deltas

one and two sometimes a little hard to

find but

and remember next to each of these

deltas you have

two diverging lines that go around the

pattern

called typelines with accidental

here's one and here's another

all right well what makes a a plane what

makes a whirl a plane whirl

well the first thing you do is of course

you got to find

your two deltas the next thing you do

is you draw a line a straight line

between the two deltas and

the rule is if

is you find a ridge

pattern that's going around in a circle

inside find a circle pattern inside

if even one

crosses one of these that are that go

around in a circle a complete circle

if even one of them crosses that line

and you know comes back because it's

going in in a full circle

if even one of them does that you

automatically call it

a plane whirl no other

worlds will do this will follow this

behavior

this is called a plain whirl all right

well what about the central pocket loop

world

so you so you notice here well yeah i

don't see

i mean i do see some circles in here

but none of them would cross that line

if we drew a line

let's take a look so let's just draw it

here

let's follow any line and any ridge

pattern

inside and you can see that they all

cross

they may cross but they don't go back

around

remember the rule was you find a

a a ridge pattern

that's going in a full circle and that

will cross the line and come back

here we don't have that we may have a

couple here that go around

but they don't cross and come back

therefore this is called a

central pocket loop whirl

all right moving right on we got the

double

loop whirl and this is pretty easy and

it's it's pretty easy to find

and um in a double loop world again

you uh you can find your deltas but

inside it looks like you have two

cores that are sort of swirling

kind of like a like a yin yang um

and that's and that's it it's it's a

whirl

because you have two deltas and it's a

double loop world because you have

two sort of like these two cores

in the inside kind of looks like a yin

yang that's your double loop world

and finally the rule for accidental

is one either if

you find two or more different types of

patterns

inside or

if it just doesn't follow any of the any

of the other rules it's automatically

called

an accidental so here we have we have

two deltas so that makes it a whirl but

it's not a plain world it's not a

central pocket loop world

why well i mean i do see a pattern

inside but it almost looks like you have

a second

pattern inside so that's a whirl

and it's a um

as well as having lines come out that

this this this makes it um

a an accidental when you have two or

more

patterns or if it doesn't follow the

general rule

you have it automatically becomes an

accidental

accidentals are sort of hard to spot

they're pretty rare

um but uh um

but um they they they

they do a a uh you know you will find

them every once in a while

so that's your uh so that's your

accidental

uh world all right so

that's that's pretty much it so in

conclusion

let's just make a table here and let's

let's

let's draw in i want you to to to to

make a little table

and i want you to to practice making

these loops

that way on on a test it's it's it's

easy for you it's second nature

and and again remember um that

loops are uh remember these percentages

loops make up about sixty percent of all

fingerprints

arch is about five and and world's about

35 percent

um remember your deltas your loops have

one delta

arches have zero and your worlds have

two deltas and if we just draw this in

here

your your ulnar

if this was a right uh let's see here so

now if you're if this is an actual

print and you're printing it on a sheet

of paper

notice how they enter and exit

towards your pinky finger because now

your hand is facing down it's your hand

is

um not supine but it's prone in other

words you're

you know you're actually pushing you

know making a print

um on on a table on a sheet of paper

so that's why it's going the other way

now because you're not look it's not

facing you it's not looking up into a

microscope

so they're going towards the ulnar bone

the ulna

which is the which makes it the ulnar

loop

an ulnar loop if it's going this way

it's down it's going to well the other

the thumb side now if this is the right

hand

thumb side that makes it a radial loop

and notice you have one delta for

any loop plane arch just kind of goes up

and down

nice and gradual no deltas whatsoever

but a tented arch is pretty sharp

comes up sharp and comes back down real

real real

dramatic with all

worlds now you always have you always

got to have two deltas well

with in a plane whirl you got to have at

least one

circulating ridge that will cross

the line and come back in central pocket

loop

will will

you'll have two deltas but none of the

lines that are

going around in a circle will cross the

line

and come back double loop whirl

you'll have sort of two cores in there

and and an accidental world you're going

to have two

or more patterns here we have a double

loop

and we have a line a ridge line that

will

that will actually a circulating ridge

line that will

cross and come back so you have two or

more different types of patterns

making this an accidental world

all right well i want you to

take your time with this as you commit

each of the eight fingerprints to memory

try drawing each of them by hand

just like just like we saw here while

explaining

how each one differs from the rent from

the rest

once you feel you got a good handle

watch i want you then to watch the

second video

to go over the minutiae and

finally you'll want to test your

knowledge assess your comprehension

using the third video that i've made for

you

and so you can really see

what you know and what you don't know to

really test your

knowledge thank you for your time

everyone

and your concentration and study well

and we'll see you in the next one