Expert review of documents by means of the colorimetric method

In forensic investigation practice the problem of defining the time sequence of written and printed texts application is essential in the cases when these texts do not have intersection regions. We suggest solving this problem by means of the metallographic examination of the documents specimens and the analysis of the obtained data colorimetric properties. The basis of the suggested method is a specific color change of the toner particles sprayed on a sheet of paper, covered with a paste layer and observed with a microscope in reflected light. The article presents experimental results for evaluating the colorimetric properties of the toner particle in the cases of written and printed texts application in different sequences. For both cases we have found out representative values of the color change.

References

[1] Dosova A.V. Teoreticheskie i prakticheskie osobennosti kompleksnogo kriminalisticheskogo issledovaniya dokumentov s izmenennymi rekvizitami. Diss. kand. yurid. nauk [Theoretical and practical features of complex forensic processing of documents with changed requisites. Kand. jur. sci. diss.]. Volgograd, 2014, 233 p.

[2] Michael J. Allen foundations of forensic document analysis: theory and practice. Wiley-Blackwell, 2015, 264 p.

[3] Vodolazov A.V., Vashkevich N.A. Laser ablation and its scopes of application. Voprosy kriminologii, kriminalistiki i sudebnoy ekspertizy, no. 1(41), 2017, pp. 136–140.

[4] Stepanov A.P. Some aspects of criminalistic examination of laser printing equipment and documents printed by it. Vestnik Astrakhanskogo gosudarstvennogo tekhnicheskogo universiteta [Vestnik of Astrakhan State Technical University], no. 5, 2007, pp. 199–202.

[5] Judd D.B., Wyszecki G. Color in business, science, and industry. Wiley-Interscience, 1975, 576 p. (Russ. ed.: Tsvet v nauke i tekhnike. Moscow, Mir Publ., 1978, 592 p.)

[6] Sharma G., Bala R. Digital color imaging handbook. CRC Press, 2003, 840 p.

[7] Logvinenko A.D. The geometric structure of color. Journal of Vision, 2015, vol. 15, no. 1, pp. 1–9.

[8] Fairchild M.D. Color appearance models. Wiley, 2005, 408 p.

[9] Robertson A.R. Historical development of CIE recommended color difference equations. Color Research & Application, 1990, vol. 15, no. 3, pp. 167–170.

[10] Colorimetry — Part 4: CIE 1976 L*a*b* Colour Space. CIE Draft Standard. 2007. CIE, 12 p.