Comparative

What techniques can be used for blood prints?

- Amido black

What is a tool?

- An object used to gain mechanical advantage. - Also the harder of two objects which when brought into contact with each other, results in the softer one being marked

What does ACE-V stand for?

- Analysis - Comparison - Evaluation - Verification

What did Ivan Vucetich do?

- Argentinean - Created fingerprint classification system "Vucetichissimo"

What are the characteristics of a plastic print?

- Caused by touching some semi-solid substance cable of retaining a 3D representation of the friction ridges *i.e. putty, wax, wet paint, grease, etc.

What happens during the step of extraction?

- Continued backward movement of the bolt or slide/breech face in semi-automatic weapons causes the extractor to "pull" the cartridge case out of the chamber. - Again, the shooter manually performs this action in other types of guns.

What are the characteristics of latent (invisible) prints?

1) Cannot be seen without development 2) Composed of sweat and body oils 3) Can be positive or negative *i.e. could leave behind (oils) or take with you (fingerprint left on a dusty counter)

Different ways to make paper

1) Chemical pulping 2) Mechanical pulping 3) Deinked pulp

How does cyanoacrylate fuming work?

1) Clear liquid polymerizes into a white residue with heat and humidity that adheres to fingerprints. 2) Can possibly overprocess and lose detail.

How does rhodamine 6G work?

1) Cyanoacrylate fuming is performed first. 2) Solution is applied to the item. 3) Visualization is done with 450-480 nm alternative light source (blue) and orange goggles.

How does basic red work?

1) Cyanoacrylate fuming is performed first. 2) Solution is applied to the item. 3) Visualization is done with 470-550 nm alternative light source (green) and orange goggles.

How do you determine the primary for the Modified Henry?

1) Determine the number of whorls on even-numbered fingers (based on ten-print card) using the following values if a whorl is present: 16, 8, 4, 2, 1 and add 1 to that final summation. 2) This number goes in the numerator. 3) Determine the number of whorls on odd-numbered fingers (based on ten-print card) using the following values if a whorl is present: 16, 8, 4, 2, 1 and add 1 to that final summation. 4) This number goes in the denominator.

Things to look for in altered typed documents

1) More than one type design used 2) More than one typewriter used 3) Check vertical, horizontal, and margin alignment 4) Check amount of ink deposited 5) Date of preparation

Limits of evidence for handwriting comparisons

1) Non-original evidence 2) Limited amount of evidence 3) Limited comparability of writing 4) Poorly skilled writing 5) Lack of individual characteristics

What are the characteristics of a plain whorl?

1) One or more ridges which make or tend to make a complete circuit 2) Two deltas with between which an imaginary line can be drawn with at least ONE recurving ridge is touched

Types of document examination

1) Physical characteristics: weight, special coatings/finishes 2) Watermark examination: true or artificial watermark 3) Fiber analysis: pulping method, paper use, etc. 4) Chemical analysis: starch content, fillers present, optical whitener

What development techniques are destructive?

1) Physical developer 2) Amido black on porous surfaces if overprocessed

How does Gentian violet/crystal violet work?

1) Powder is dissolved in water. 2) When applied, the powder preferentially adheres to the print residue instead of the adhesive side of the tape. 3) After applied, the tape is rinsed with water.

What are the functions of the skin?

1) Protects underlying tissues from environmental factors (i.e. infection) 2) Prevent uncontrolled water loss 3) Control water/salt equilibrium

Characteristics of skilled writers

1) Rapid movement 2) Smooth continuous stroke 3) Rhythmic execution of writing line 4) Even shading 5) Flow

How does ninhydrin work?

1) Reacts with amino acids to form Ruhuemann's purple since the amino acids do not diffuse through the paper 2) Requires heat and humidity to develop

What are the characteristics of an angular tented arch?

1) Ridges enter upon one side and flow out on the other like plain arches while doing something different in the middle (tented arch) 2) Formed by 2 ridges meet at an angle of 90 degrees or less

Fountain pen ink

Dye or pigment suspended in water Leaves 2 lines from nib

What does ESDA stand for and do?

ElectroStatic Detection Apparatus Analyzes pages below where a sample was written (i.e. ransom note was written on a pad that was recovered and the impression of the writing could be seen)

Significance of Leopold and Loeb case

Exemplars where used to eliminate Loeb and identify Leopold based on the hand printed envelope

Class characteristics

Features shared by two or more shoes/tires: 1) General design 2) Physical size and shape (actual, not manufacturer) 3) General conditions and wear pattern

Where is the stratum granulosum located?

In the epidermis of the skin

Where is the stratum papillae located?

In the epidermis of the skin

Where do sebaceous glands empty?

Into the the hair follicle

How does physical developer work?

It is an aqueous solution of silver ions, a ferrous/ferric redox system, buffer, and detergent. - Silver particles deposit preferentially on prints so the prints appear dark grey. - Destructive process

Significance of Hoffman case

Known Harris signature was found be not genuine Hoffman convicted of murder and forgery

What are the requirements for a MEETING whorl tracing?

Less than 3 ridges in either direction

Factors of using non-original documents

Loss of fine details like striation marks, pen lifts, pen stoppages, retouching, and line quality Also, from copying process itself, handwriting can be manufactured or manipulated from a genuine document

How does powdering fingerprints work?

The powder binds to the substances that make up the latent print and is applied with a brush.

What is the chamber of a gun?

The rear part of the barrel bore that has been formed to accept a specific cartridge * Revolver cylinders are multi-chambered.

What is ballistics?

The study of projectiles in motion

How do gel lifters work?

They use clear acetate on the adhesive side of tape and show the mirror image of the print. Need software to flip over the image to its original orientation.

How do rubber lifters work?

They use neoprene on the adhesive side of tape and lift the mirror image of the print. Need software to flip over the image to its original orientation.

What direction do ulnar loops open towards?

Towards the pinky finger (ulna) of that hand (need to know which hand the print came from)

What direction do radial loops open towards?

Towards the thumb (radius) of that hand (need to know which hand the print came from)

Pictograph

Use of pictures to represent words

Grapheme

Use of symbols for written language

Logograph

Use of symbols to represent a word or phrase

Ideograph

Use of symbols to represent an idea

Phonoeme

Use of symbols to represent sounds

Significance of Weinberger kidnapping

Used DMV records to match questioned and known writing samples

What does VSC stand for and do?

Video Spectral Comparator Uses different wavelengths of light to excite and see different things on the sample. Non-destructive technique

What did Alphonse Bertillon do?

- Created Bertillon system of identification (Anthropometry) - Based 11 measurements of certain bony structures of the body - Includes the following 2 assumptions: 1) Assumed skeletons remain unchanged after age 20 2) Assumed all people would perform the measurements exactly the same

What did Edward Henry do?

- Created Henry classification system for fingerprints

How does silver nitrate work?

- Detects chloride components in eccrine secretions

What did Francis Galton do?

- Established individuality and permanence of fingerprints - Forwarded letter from Faulds to Darwin

How do you determine the core with an even number of spikes?

- For even number of spikes as high as the shoulders, the core is located on the end of the farthest of the innermost spikes from the delta and can touch the inside of the recurve

How do you determine the core with an odd number of spikes?

- For odd number of spikes as high as the shoulders, the core is located on the end of the center spike and can touch the inside of the recurve

What does rifling mean?

- Helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis. - This spin serves to gyroscopically stabilize the projectile, improving its aerodynamic stability and accuracy.

Where are apocrine glands located?

- In axillary and genital areas

What happens during the step of unlocking?

- In semi-automatic weapons, the gas expansion causes a backward movement of the bolt (rifles/shotguns) or slide/breech face (pistols) unseating the cartridge case from the chamber and engaging the disconnector (which prevents fully automatic fire). - In bolt and lever action rifles, pump and break-open shotguns, and revolvers, the shooter manually performs the unlocking.

How do you determine the core with interlocking loops?

- Join the loops together to make one loop with spikes inside (see notes)

Where are sebaceous glands located?

- Located chest, back, face, scalp, breast, and genital area

What did Henry Faulds do?

- Performed experiments of removing skin on fingers and comparing before and after prints - Published letter regarding uniqueness and permanence of fingerprints - Medical missionary to Tokyo, Japan - Had controversy with Herschel

What happens during the step of cocking?

- Place a firing mechanism under tension - During the backward movement of the bolt or slide/breech face while extraction/ejection is taking place, the hammer or striker is engaged by the sear and cocked for the resumption of the cycle of operations. The shooter manually performs this action in other types of weapons. - Note: In double action and double action/single action guns, cocking and firing are incorporated into the action of the trigger pull.

Where are eccrine glands located?

- Secretory bodies in subcutaneous layers - On palms of hands and soles of feet

Of what are sudoriferous and sebaceous glands based?

- Sudoriferous: water-based - Sebaceous: oil-based

What happens during the step of chambering?

- The cartridge, held in place by the extractor, is pushed into the barrel chamber by the bolt (rifles, semi-auto shotguns) or breech face (semi-auto pistols, lever-action rifles, break-open shotguns). - Revolver ammunition is rotated into place by the movement of the cylinder.

How do you determine the core with one spike?

- The core would be located on the spike in the center of the innermost recurve provided it rises as high as the shoulders

What is the caliber of a gun?

- The diameter of the bore of a rifled firearm - Measured in hundredths of an inch or millimeters

4 Rules of Gun Safety

1) All guns are always loaded - treat them as such. 2) Never let your muzzle cover anything you are not willing to destroy. 3) Keep your finger off the trigger until your sights are on the target. 4) Be sure of your target, backstop, and beyond.

What characteristics have the potential for distortion?

1) Anatomical aspects 2) Pressure distortion 3) Deposition pressure 4) Development medium 5) Matrix 6) Substrate

Types of identifying marks found on fired cartridges

1) Breechface marks 2) Firing pin impressions 3) Chamber marks 4) Extract and ejector marks

What are the characteristics of patent (visible) prints?

1) Can be seen without enhancement 2) Composed of sweat, body oils, and foreign substances (ex. blood or paint) 3) Main difference from latent is the substrate

How do you determine the secondary for the Modified Henry?

1) Determine the pattern on the index fingers with the following designations: U = ulnar loop R = radial loop W = whorl A = arch T = tented arch 2) Designation for finger #2 goes in the numerator. 3) Designation of finger #7 goes in the denominator.

How do you determine the final for the Modified Henry?

1) Determine the ridge count for #5 and would go in the numerator. 2) If #5 is not a loop, then look at #10 and would go in the denominator. 3) If neither finger is a loop, then the final is not used. 4) If all 10 fingers are whorls, then #5 is counted as an ulnar loop.

How do you determine the key for the Modified Henry?

1) Determine the ridge count for the first loop other than #5 and #10. 2) This always goes in the numerator.

How do you determine the subsecondary for the Modified Henry?

1) Determine the whorl tracing (I, O, or M) or ridge count (based on the values below) for finger 2-4 for the numerator. 2) Determine the whorl tracing (I, O, or M) or ridge count (based on the values below) for finger 7-9 for the denominator. Fingers 2 & 7: I = 1-9, O = 10+ Fingers 3 & 8: I = 1-10, O = 11+ Fingers 4 & 9: I = 1-13, O = 14+ *Note: Subsecondary is not done if there are small letters.

What techniques can be used for eccrine secretions?

1) Direct visual methods 2) Dusting powders 3) Ninhydrin 4) Vacuum metal deposition 5) Cyanoacrylate fuming 6) Silver nitrate 7) Fluorescence examination *These methods interact with water

What are the characteristics of deposition pressure?

1) Downward force 2) Changes shape by flattening the ridges 3) Doesn't change the orientation of ridges --> can still compare

What are the steps to do ridge counting?

1) Draw a line between the delta and core. 2) Count the number of ridges the line crosses, not counting the delta and the core. Notes: *At least one ridge must be a looping ridge. *Fragments and dots are counted if they appear as thick as the surrounding ridges. * If bifurcation is crossed, each arm is counted. *If the delta is located on the only looping ridge, there is no ridge count. * White space must intervene between the delta and the first ridge count.

What are the types of sudoriferous glands?

1) Eccrine 2) Apocrine

4 components of what a QD examiner does

1) Establishes genuineness or not/ expose forgery, reveal alterations, additions, deletions 2) Identify or eliminate persons as the source of handwriting 3) Identify or eliminate the source of typewriting or other impression marks or relative evidence 4) Write reports and give testimony

What are the steps of the cycle of firing?

1) Feeding 2) Chambering 3) Locking 4) Firing 5) Obturation 6) Unlocking 7) Extraction 8) Ejection 9) Cocking

How does amido black work?

1) Fix print with methanol before processing. 2) Uses naphthol blue black B (methanol- or aqueous-based) which binds to proteins in blood and bodily fluids 3) Prints appear a blue-black color.

How does vacuum metal deposition work?

1) Gold is evaporated under vacuum to form a thin layer on object, penetrating the fingerprint (shows the ridges). 2) Zinc is deposited under the vacuum coating (shows the valleys). 3) Can be followed with cyanoacrylate fuming.

What does the dermal papillae do?

1) Holds the layers together 2) Produces friction ridges 3) Interdigitates with the epidermis

What is the test for appendages (i.e. spolied vs. good curves)?

1) If you can trace around the recurve and the appendage flows off smoothly, it is not spoiled. 2) If spoiled, use the next recurve outside of it that is free of appendages. 3) Dots do not count. (Refer to notes for visualization)

What is a core?

1) It's placed upon or within the innermost sufficient recurve 2) Located on the shoulder of the innermost loop farthest from the delta

Characteristics of forged signatures

1) Lack of individuality 2) Slowly written 3) Unnatural appearance 4) Identical to known 5) Lacks rhythm 6) Presence of guidelines 7) Inconsistent letter formation

What are the characteristics of pressure distortion?

1) Lateral force 2) Fingers slide in one direction at a time *Multiple directions = multiple prints

Limits of the examiner for handwriting comparisons

1) Limited training 2) Limited experience 3) Limited time 4) Poor or no methodology

Characteristics of individualized handwriting

1) Line quality 2) Word and letter spacing 3) Pen lifts 4) Connecting strokes 5) Beginning and ending strokes 6) Unusual letter formations 7) Shading 8) Slant 9) Base line placement 10) Use of stylistic strokes 11) Placement of diacritics 12) Formatting 13) Size Ratio

How do you determine the major for the Modified Henry?

1) Look at left hand first. 2) Determine the value of the ridge count (based on the values below) or whorl tracing (I, O, or M) for finger #6 which goes in the denominator. 3) Determine the value of the ridge count (based on the values below) or whorl tracing (I, O, or M) for finger #1 which goes in the numerator. Ridge count for finger #6: S = 1-11 M = 12-16 L = 17+ If an L is used for #6, use this for the ridge count of #1: S = 1-17 M = 18-22 L = 23+ *Note: A small letter in one or both thumbs eliminates the major.

How do you determine the small letters for the Modified Henry?

1) Look for any arches and tented arches in any finger or radial loops in any finger other than the index fingers. 2) Look at either side of #2 and #7 and classify on either side of the secondary using dashes for ulnar loops or whorls only to the right of the secondary. 3) The right hand in the numerator, and the left hand in the denominator. (i.e. R-t / aTr where the capital letters are aligned on top of each other) *Note: Small letters replace the subsecondary.

What are the components of amido black and their purposes?

1) Methanol- fixes the print prior to processing 2) Naphthol Blue Black B- binds to proteins in blood and bodily fluids

How does powder suspension processing work?

1) Mix Lightning powder with water and detergent. 2) Paint the mixture on the adhesive side of the tape. 3) Rinse with water. 4) Reapply mixture if needed.

What are the characteristics of a recurving tented arch?

1) Ridges enter upon one side and flow out on the other like plain arches while doing something different in the middle (tented arch) 2) Has two of the three characteristics of a loop (i.e. lacks either sufficient recurve, delta, or ridge count)

What are the characteristics of an upthrust tented arch?

1) Ridges enter upon one side and flow out on the other like plain arches while doing something different in the middle (tented arch) 2) One or more ridges at the center form an upthrust greater than 45 degrees 3) Must change direction from base line ridge 4) Must be as high as surrounding ridges as thick

What types of guns have rifling?

1) Rifles 2) Revolvers 3) Modern pistols

What are the types of actions for shotguns?

1) Single shot 2) Double shot 3) Bolt action 4) Self-loading 5) Pump action

List the types of handguns

1) Single shot 2) Revolving 3) Self-loading

Characteristics of unskilled writers

1) Slow movement 2) Heavy pen pressure 3) Hesitations 4) Retouches of letters 5) Irregularities in letter forms

What are the requirements for a loop?

1) Sufficient recurve 2) Delta 3) Ridge count ** Can be ulnar or radial

Significance of Lindbergh case

1) Suspect caught while spending gold certificates after they had been called to be turned in 2) Handwriting comparisons made to ransom note

Why can fingerprints be used to identify someone?

1) They are permanent and don't change throughout life (except scarring and growth). 2) They are unique to each person.

What are the steps to perform a whorl tracing?

1) Trace from the left delta to a point opposite the right delta. 2) Drop down at ending of the ridge 3) Follow lower fork of a bifurcation 4) Stop at a point opposite the right delta 5) Count the ridges between that point and the delta **Do not count delta or tracing ridge **For double loop and accidental whorls, stop at nearest point to right delta on an upward trend or the delta itself

What are typelines?

1) Two innermost ridges which start parallel, diverge, and surround or tend to surround the pattern area. (Pattern area: core, delta, and ridges used in classifying loop) 2) Not always two continuous ridges 3) When there is a break, the ridge immediately outside it should be used as it continuation 4) Arms of a bifurcation on which the delta is located can never be used for typelines 5) Angles can never used for typelines - Formed by the abutting of one ridge against another, not by a single ridge

What are the basic requirements of a whorl pattern?

1) Two or more deltas 2) Recurving ridge in front of each

What are the characteristics of a double loop whorl?

1) Two separate loop formations with two separate and distinct sets of shoulders and two deltas 2) Loop appendage rule applies 3) Center recurving ridge cannot be shared 4) No "s" type loops and no interlocking loops

What techniques can be used for sebaceous secretions?

1) Visual examination 2) Dusting powders 3) Physical developer 4) Vacuum metal deposition 5) Small particle reagent 6) Fluorescence examination 7) Gentian Violet 8) Sudan black 9) Iodine *These methods interact with oils

What are the rules for deltas?

1) When there are two or more possible bifurcation deltas which conform to the definition, the one nearest the core should be chosen. 2) The delta may not be located in the middle of a ridge running between the typelines toward the core, but at the end nearest to the core. 3) The delta may not be located at a bifurcation which does not open toward the core. 4) Where there is a choice between a bifurcation and another type of delta, the bifurcation is selected. (Refer to notes for visualization)

What are examples of non-porous surfaces?

1) glass 2) plastics 3) metals 4) varnished wood

What are examples of porous surfaces?

1) paper 2) cardboard 3) untreated woods

Auto forged signature

Disguised signature Denies authorship

What is the ejector of a gun?

The portion of a firearm's mechanism which ejects or expels cartridge(s) from a firearm

What are the requirements for an INNER whorl tracing?

3 or more ridges INSIDE the right delta

What are the requirements for an OUTER whorl tracing?

3 or more ridges OUTSIDE the right delta

What happens during the step of feeding?

A cartridge is stripped from a magazine (semi-automatics, lever and bolt-action rifles) or manually placed (single-shot bolt-action rifles, break-open shotguns, and revolvers) against a bolt or breech face.

What are the characteristics of an accidental whorl?

A combination of two different types of patterns (excludes plain arch) with two or more deltas or conforms to no other definition

What is a revolver?

A firearm (usually handgun) with a cylinder having several chambers arranged around an axis and discharged by the same firing mechanism * Uses centerfire and rimfire

Variation in regards to handwriting

A handwriting feature within the observed range of deviation More variation = more known needed No variation = unnaturalness

What is a round?

A single cartridge

What happens during the step of firing?

A trigger press rotates the sear, which sends the firing pin or striker against the primer, causing ignition of the powder. This results in gas expansion within the chambered cartridge which propels the projectile into and through the barrel bore.

What is polygonal rifling?

A type of gun barrel rifling where the traditional sharp-edged lands and grooves are replaced by less-edged "hills and valleys" in a polygonal pattern, usually taking the form of a hexagon or octagon.

What is the purpose of the primer?

An explosive substance that ignites when struck to detonate the powder in a cartridge

What is a dot?

An individual ridge unit significantly shorter than the average ridge length on the fingerprint

What are the characteristics of a central pocket whorl?

At least one recurving ridge with two deltas between which an imaginary line can be drawn and touch NO recurving ridges

Determination of the weight of paper

Based on a 500-sheet ream What's bought from the store is one-quarter the size Example: 20 lbs. paper means the 500 sheets of full ream paper weighed 20 lbs.

Individual characteristics

Features that have occurred randomly on a footwear outsole or tire tread Examples: cuts, scratches, tears, holes, stone holds, abrasions, acquisition of debris Position, orientation, size, and shape of individual characteristics contribute to uniqueness of a show or tire

What methods require processing prior to use?

Fluorescent chemicals require cyanoacrylate prior to use (Ex. Basic Red, Rhodamine 6G, Basic Yellow, etc.)

What is a bifurcation?

Forking or dividing of one line into two or more lines

Simulated forged signature

Freehand drawing of genuine signature while looking at it Can contain touch-up strokes

Two-dimensional impression

Has length and width Example: bloody shoe print on tile floor (positive impression) or sole of shoe removes dust from a dusty piece of glass (negative impression)

Three-dimensional impression

Has length, width, and height Example: shoe or tire print in dirt or snow

What is the purpose of rifling?

Imparts the spinning motion to a bullet when it's fired, stabilizes in its trajectory

What is a clip?

Misnomer for a magazine

Factors that affect writing skill level

Natural talent Education Practice Use Care Speed Health Physical state

For what conditions should small particle reagent be used?

Non-absorbent surfaces that are or have been wet

For what conditions should ninhydrin be used?

On porous surfaces and good for old prints

For what conditions should powder be used?

On smooth, non-porous surfaces with newly deposited prints

Where do eccrine glands empty?

On the skin at the tops of the ridges

Cognitive bias

Opinion(s) influenced by subjective perception whereby, inferences are made in order to arrive at a conclusion

Traced forged signature

Prepared by using a genuine signature Done using carbon paper, transmitted light Doesn't have all the features found the in genuine signature Doesn't relate to authorship

What happens during the step of ejection?

Prior to the termination of backward movement of the bolt or slide/breech face, the cartridge case being pulled by the extractor comes in contact with the ejector which "pushes" the spent cartridge case through the ejection port.

What is a delta?

The point on a ridge at or nearest to the point of divergence of typelines, and located at or directly in front of the point of divergence

What does gauge mean relative to shotgun projectiles?

Refers to the diameter of the barrel on a shotgun in terms of the number of lead balls the size of the bore it would take to weigh one pound (12 gauge is the diameter of a lead ball weighing 1/12 of a pound.)

What does beech face mean?

Refers to the front part of the breechblock that makes contact with the cartridge in a firearm

What does cannelure mean?

Refers to the groove or fluting around the cyclindrical part of the bullet

What does it mean if a firearm is semi-automatic?

Requires a separate pull of the trigger for each shot fired and uses the discharge to perform a portion on the firing cycle

What are the characteristics of a plain arch?

Ridges enter on one side and flow or tend to flow out other with a rise or wave in the center

What happens during the step of obturation?

Sealing of gases due to the expansion of a cartridge case as a result of chamber pressure

What types of guns don't have rifling?

Shotguns

What methods require manipulation after processing to recover the original print orientation?

Since they produce mirror images of the print: 1) Gel lifters 2) Rubber lifters

Fiber tip pen ink (markers)

Suspended in alcohol Flows deeply into paper fibers

Ballpoint pen ink

Suspended in alcohol No feathering

Carbon ink/ India ink

Suspended in either water or alcohol

What happens during the step of locking?

The bolt/breech face/cylinder is locked into position with the bore/barrel. Through locking, the mechanical alignment of the major parts within the firearm will ensure gas expansion is captured and focused on propelling the bullet through the bore and ensuring the operation of a semi-auto firearm. Once locked, the weapon is ready to fire.

What is a magazine?

The container for cartridges that has a spring and follower to feed those cartridges into the chamber of the firearm. *Could be detachable or an integral part of the firearm

What is firearms identification?

The determination of whether a bullet or cartridge was fired by a certain weapon

What is the muzzle of a gun?

The end of a firearm where the projectile comes out

What does it mean if a firearm is automatic?

The firearm feeds, fires, extracts, and ejects cartridges as long as the trigger is fully depressed and cartridges are in the system

What is the bore of a gun?

The interior of the firearm barrel

What is the extractor of a gun?

The mechanism for withdrawing the cartridge or cartridge case out of the chamber

What is a ridge ending?

The point at which a ridge terminates

Simple forged signature

Written without the benefit of knowledge of the genuine signature Most common type of forgery