ABSTRACT
ObjectiveTo establish a method for rapid identification of bloodstain age.MethodsUnder laboratory conditions(20 ℃, 25 ℃and 30 ℃), an integrating sphere ISR-240A was used as a reflection accessory on an UV-2450 UV-vis spectrophotometer, and a standard white board of BaSO4 was used as reference, the reflection spectrums of bloodstain from human ears’venous blood were measured at regu-lar intervals. The reflection radiosR541 andR577 at a specific wavelength were collected and the value of R541/R577 was calculated. The linear fitting and regression analysis were done by SPSS 17.0.ResultsThe results of regression analysis showed thatR2 of the ratios of bloodstain age to UV visible reflectivity in specific wavelengths were larger than 0.8 within 8 hours and under certain circumstances. The regression equation was established. The bloodstain age had significant correlation with the value ofR541/R577.Con-clusionThe method of inspection is simple, rapid and nondestructive with a good reliability, and can be used to identify the bloodstain age within 8 hours elapsed-time standards under laboratory conditions.