Lip print enhancement: review

Figures & data

Table 1. Physical and chemical enhancement methods for LPs.

Reference	Design details	Results
Seguí et al. (2000), [13]	Persistent lipstick was applied on the lips of volunteers, and then pressed on ceramic, glass, cotton fabric, and white paper substrates. LPs on each substrate were enhanced with developers (aluminium powder, cobalt oxide powder, and magnetic powder) after exposure to ambient conditions.	Identifiable LPs were obtained up to 30 days after deposition. Aluminium powder and magnetic powder gave better enhancement efficiency than magnetic powder.
Dolly et al. (2016), [18]	Visible and latent LPs were produced on various supports (white cotton fabric, white satin fabric, and white clay cup) from 60 individuals and developed using Sudan III dye, indigo blue dye, and aluminium powder.	Sudan III dye and aluminium powder showed significant enhancement of visible LP. Indigo dye is useful for developing both visible and latent LPs.
Khanna et al. (2010), [3]	Traditional and long-lasting lipsticks were used to obtain visible and latent LPs, respectively, from 45 volunteers on bone China cup, white satin fabric, and white cotton fabric. Samples were developed by dusting with a camel hair brush and were lifted using an appropriate adhesive tape.	There was no appreciable difference between the enhancement efficiency by natural (vermilion and indigo dye) and lysochrome (Sudan Black) dyes.
Fonseca et al. (2014), [19]	Latent LPs were produced on metallic straw (bombilla). Volcano, fluorescent, and Silk Black volcano powders were utilised for print enhancement.	White volcano powder was most effective for LP development, followed by fluorescent powder and Silk Black volcano powder.
Castello et al. (2002), [27]	Lipstick was applied on the lips of 10 volunteers. Prints were produced and developed on tissue paper and white cotton fabric using lysochrome dye (Sudan III, Sudan Black, and Oil Red O), ninhydrin, and fingerprint (FP) powders (FP red powder, FP black powder, and silver metallic powder).	There was a quality enhancement of prints on both substrates using solution or powder lysochrome dyes (in the order: Sudan Black > Oil Red O > Sudan III). Ninhydrin produced a negative result.
Navarro et al. (2006), [29]	A total of 17 corpses were utilised. A mould made of silicone was created to simulate the human lip. A protective or long-lasting lipstick was spread on the mould and afterwards pressed against the corpse’s skin (right side of the neck and the anterior region of the forearm). Development of LP was initialised with powder lysochromes (Sudan III, Sudan Black, and Oil Red O).	Sudan Black produced better results than Sudan III and Oil Red O in terms of enhancing latent LPs.
Kumar et al. (2010), [4]	Latent LPs of 200 participants were made on a rough surface without applying any lipstick. Prior to print production, each lip was cleaned with gauze moistened in saline water and dried with sterile cotton. Lysochrome dye (Oil Red O) and fluorescent dye (Nile Blue) were utilised for latent LP enhancement.	There were clear and well-defined lip grooves and wrinkles in prints developed with fluorescent dye relative to those enhanced with lysochrome dyes.
Castelló et al. (2005), [30]	The study utilised existing pre-existing latent LP (over 1 year old) produced on a colored substrate. Nile Red (fluorescent dye), both in powder and as an alcoholic solution, were used to develop prints. UV light (320–400 nm) and an alternate light source (390–520 nm) were utilised for print visualisation.	Good-quality prints (with well-defined shapes and outlines) were obtained with fluorescent dye (Nile Red).

Seguí MA, Feucht MM, Ponce AC, et al. Persistent lipsticks and their lip prints: new hidden evidence at the crime scene. Forensic Sci Int. 2000;112:41–47.

 Web of Science ®Google Scholar

Dolly A, Rodrigues C, Bankur R, et al. Evaluation of efficacy of three different materials used in cheiloscopy—a comparative study. J Clin Diagnostic Res. 2016;10:ZC67–ZC71.

 Google Scholar

Khanna S, Singh N, Brave V. Natural dyes versus lysochrome dyes in cheiloscopy: a comparative evaluation. J Forensic Dent Sci. 2010;2:11.

 Google Scholar

Fonseca G, Bonfigli E, Cantin M. Experimental model of developing and analysis of lip prints in atypical surface: a metallic straw (bombilla). J Forensic Dent Sci. 2014;6:126.

 Google Scholar

Castello A, Alvarez M, Miquel M, et al. Long-lasting lipsticks and latent prints. Forensic Sci Commun. 2002;4:2–6.

 Google Scholar

Navarro E, Castelló A, López JL, et al. Criminalystic: effectiveness of lysochromes on the developing of invisible lipstick-contaminated lipmarks on human skin: a preliminary study. Forensic Sci Int. 2006;158:9–13.

 PubMed Web of Science ®Google Scholar

Kumar P, Mastan KM, Patil S. Cheiloscopy: efficacy of flouroscent dye over lysochrome dye in developing invisible lip prints. J Contemp Dent. 2010;1:3–7.

 Google Scholar

Castelló A, Alvarez-Seguí M, Verdú F. Luminous lip-prints as criminal evidence. Forensic Sci Int. 2005;155:185–187.

 PubMed Web of Science ®Google Scholar