Which chemical is best for locating fingerprints on the sticky side of tape?

Gentian violet is particularly effective for developing fingerprints on the sticky side of tape due to its ability to adhere to the protein content in fingerprint residues. When applied, it forms a visible stain that highlights the ridge patterns, making them much easier to see and analyze. This is crucial in forensic investigations, as fingerprint identification relies heavily on the clarity and contrast of the print impressions.

Superglue, although useful for developing fingerprints on non-porous surfaces, does not work well on sticky surfaces like tape because the chemical properties of cyanoacrylate are not conducive to interacting with the adhesive. Acetone, primarily a solvent, could potentially damage the adhesive or the fingerprint residue rather than develop it, while "alphabet soup" is not a viable option as it lacks any chemical properties relevant to fingerprint development. Therefore, gentian violet stands out as the most suitable choice for this specific task in forensic analysis.