Latent fingermark recovery in a simulated café setting: an exploratory study of cyanoacrylate fuming on disposable nonporous plastic and semiporous paper cups

Latent fingermark recovery from beverage containers is an important aspect of forensic investigations, yet the influence of substrate properties and beverage temperatures on fingermark development remains understudied. This exploratory study assessed the development and quality of latent fingermarks on disposable beverage cups made of nonporous plastic and semiporous paper using cyanoacrylate (CA) fuming, under conditions approximating a typical café environment. A total of 255 cups (107 plastic, 148 paper) were collected after participants consumed hot and iced beverages in a controlled classroom setting. CA fuming was performed under standardized laboratory conditions, and developed prints were evaluated on a five-grade scale (Grade 1 = poor quality, Grade 5 = very good quality). Analyses revealed significantly more and higher-quality latent fingermarks on plastic cups compared with paper cups, with Grade 5 prints observed exclusively on plastic surfaces. Among plastic cups, transparent cups yielded more identifiable prints than translucent ones. These findings highlight the potential impact of porosity, surface texture, and handling behaviors on fingermark residue preservation and polymerization during CA fuming. This study underscores the effectiveness of plastic beverage cups as substrates for latent fingermark recovery with CA fuming, whereas semiporous paper cups may require different or enhanced development techniques. Repetitive gripping of hot beverage cups—intended to avoid burns—may mechanically disrupt residues or shorten handling times, thus reducing overall residue deposition. Limitations such as the relatively homogeneous participant pool, reliance on a single examiner for grading, and controlled environmental conditions should be addressed in future research. Nonetheless, this work offers insight into the forensic viability of common beverage containers and provides a foundation for further investigations in real café settings. Future studies are encouraged to expand participant diversity, explore varied environmental conditions, and compare alternative fingermark development methods to optimize practical applications and casework outcomes.