A study has demonstrated that by trimming the illumination wavelength and narrowing the viewing bandwidth, markedly better results can be achieved when examining fingerprints treated using 1,2 Indandione.

When 1,2 Indandione was first proposed as a fingermark development reagent in 1997, researchers quickly saw its potential as a low-cost alternative to DFO for the development of fluorescent marks on porous materials including paper.

To achieve the best possible results, most research suggests that evidence is dipped, washed, or sprayed with a working solution of 1,2 Indandione dissolved in ethyl acetate and HFE 7100, before being heated to 100oC for a period of time dependent upon the method of heating.

Finally, the evidence should be examined using either a BLUE/GREEN (445-510) or GREEN (515-570nm) forensic light source with fluorescence being observed via an ORANGE viewing filter.

Superior Results
This study, using 1,2 Indandione to develop marks on white and brown envelopes, demonstrates that superior results can be achieved by ‘trimming’ the output wavelength of the light source and ‘narrowing’ the visible bandwidth of the viewing filter.