Removal of cyanoacrylate residues from compact discs (CDs) while preserving digital evidence

The preservation of digital data during fingermark development is critical to maintaining the evidential integrity of optical storage media in forensic investigations. Cyanoacrylate (CA) fuming, a widely used technique for visualizing latent fingermarks, may leave polymerized residues that threaten the structural and data integrity of compact discs (CDs). This study aimed to identify a safe and effective cleaning approach that enables complete data recovery after CA fuming and subsequent dye staining without causing physical or chemical degradation of the substrate. A three-phase experimental protocol was designed, including pre-examination, formulation, and validation stages. During preliminary testing, various solvent systems were screened for their ability to remove polymerized CA while preserving disc readability. An acetone-methanol mixture in a 1:2 (v/v) ratio was determined to be optimal, effectively dissolving CA and dye residues without inducing delamination or deformation of the data layer. Validation experiments using CDs from multiple manufacturers confirmed full data accessibility after treatment, verified by sector-by-sector readout analysis. The results demonstrate that this formulation provides a practical and reproducible post-development cleaning procedure for forensic laboratories. Given its compatibility with optically sensitive polymeric substrates, the proposed method offers a reliable approach to balancing fingermark visualization and digital data preservation in forensic chemistry practice.