Is a forensic investigation technique that deals with identification of humans based on lips traces.

• 1950 La Moyne (The Father of Cheiloscopy)
• In his book labeled as “HOMI- CIDE INVESTIGATION “he said that as finger prints lips also possess distinctive lip prints for each and every person.
• Lip prints, like fingerprints are unique to an individual and can be easily recorded. Identification plays a major role in any crime investigation.
• The pattern of wrinkles on the lips has individual characteristics like fingerprints

How To Search Lip Prints On Crime Scene?

• The search for possible Lip Prints needs a systematic and narrowly approach to the suspected areas.
• A magnifying lens is useful to locate and judge the quality of the Lip Prints.
• Traces of lips should be looked for on cutlery and crockery items, on the window or door glass and on photograph or letters. Lip print may also
  appear on side by side with tooth marks on food products.
• In practice, lip prints have also seen in the windows, painting, doors, plastic bags and cigarette ends.
• Observation under white light may reveal latent Lip Prints that can be photographed without any further treatment.
• Lip Prints can frequently be seen by holding the flashlight at low angles so that the surface is observed under oblique lighting.
• In some cases, latent print can often be detected using episcope coaxial illumination. The print is, therefore, visible as dark ridges against a light background.
• The process is concerned with recognition, examination, identification, individualization, and evaluation.
• Development of Lip prints
  • Powder Method
  • Chemical Method
  • X-Ray Method

Classification

In 1967 Santos was the first person to classify lip grooves. He divided them in to four types namely:

• Straight line
• Curved line
• Angled line
• Sine-shaped line

Tsuchihasi Classification Suzuki and Tsuchihashi, in 1970 devised a classification method of lip prints as follows:

• Type I: A clear-cut groove running vertically across the lip.
• Type I’: Partial-length groove of Type I.
• Type II: A Branched groove. It include branch grooves across the whole lips.
• Type III: An intersected groove. It include grooves which are intersecting each other.
• Type IV: A Reticular pattern. In this type lips contains rectangular grooves.
• Type V: Other patterns. Grooves which don’t fall in any of the above four categories and can’t be differentiated morphologically.

Lip grooves

A Complete Vertical/Vertical
B- Incomplete
C- Complete Bifricated/Brificated
D- Incomplete
E- Complete Branched/Branched
F- Incomplete
G- Reticular Pattern
H- Cross Form
I- Horizontal/Complete Horizontal
J- Horizontal with other forms

Forms of Lip

Lip prints are available particularly in the following forms–

• Visible Lip Prints – These are the Lip Prints which are visible to the unaided eye and it does not need any further development for its visualization.
• Latent or Hidden Lip prints – These are the Lip Prints which are not visible to human eye. It requires further development processes for its visualization.
• 3-D or Plastic Lip Prints – These are the Lip Prints which are found on soft, gel like surface (wax or butter). They are visible to unaided eye but sometimes need develop processing for photography.

Uses of Lip Prints

• Lip prints have the same value as Dactyloscopy traces.
• Just like finger print and teeth, lip print can be used as tool for identification.
• Lip prints are unique and do not change during life of a person.
• They can be most frequently seen during murders, rapes and burglaries.
• Traces with clear lines and individual elements enable individual identification of human beings.