METHOD OF FINDING AND DETECTING HAND TRACES ON THERMAL PAPER AND OTHER POROUS SURFACES WITH APPLIED TEXT Russian patent published in 2019 - IPC A61B5/1172 G01N33/50 

FIELD: medicine.

SUBSTANCE: invention relates to criminalistics, forensic medicine and can be used to detect traces of organic origin, namely fingerprints and palms of hands for fingerprinting. Method of detecting traces of hands on thermal paper and other porous surfaces with applied text involves treatment of hand traces with powder and ninhydrin in two steps: first, powder consisting of iron oxides FeO:Fe₂O₃:Fe₃O₄ in ratio 1:(1–3):(1–4) respectively, with particle size 0.01–0.05 mcm, and then – solution prepared from concentrated 16–23 % ninhydrin solution based on polar solvent with further dilution nonpolar solvent in ratio of 1:(40–60).

EFFECT: invention provides obtaining well-visible contrasting traces of hands on thermal paper without destructive effect on heat-sensitive paper layer, as well as on handwritten and printed documents having impressions of seals and dies.

1 cl, 4 dwg, 3 ex