Which technique can accelerate the development of Ninhydrin treated prints?

The chosen technique, which involves heating and humidification, is particularly effective in accelerating the development of Ninhydrin treated latent prints. Ninhydrin reacts with amino acids present in sweat residues found in latent fingerprints, leading to the formation of a colored compound. The development process can be enhanced by applying heat, as it increases the reaction rate of Ninhydrin with the amino acids, resulting in more vibrant and readily visible prints.

Additionally, humidification plays a key role because Ninhydrin requires moisture to optimize its chemical reactions. The introduction of humidity can help to facilitate the interaction between the Ninhydrin and the amino acids, allowing for a more efficient development of prints.

To contrast, other techniques such as cooling and drying or freezing and drying would generally slow down the development process, as they do not provide the necessary warmth or moisture needed for optimal reactions. Dipping and brushing might provide some benefit in certain contexts but do not specifically address the enhancement of the Ninhydrin reaction as effectively as heating and humidification do. Thus, the combination of heat and moisture is the most effective for accelerating the development of Ninhydrin treated prints.