![]() ![]() The wall was first painted with two coats of Glidden Speed-Wall interior PVA Primer #GL 1050-1200 white. section of half inch drywall was obtained for the experiment. None of the authors discussed methods for paint removal.Ī 4 ft. The third coat of paint made the bloodstains either not visible or “questionable” in appearance with the light sources. The author reported that the bloodstains were “visible” to “barely visible” with the use of an alternate light source after two coats of paint were applied. No statement was made regarding the type of filter used. An Omniprint™ 1000 and Polilight™ (150 watt model) were used to examine the stains under paint. In her experiment the author placed both single blood drops and blood swipes on wood and then painted over the stains with up to three coats of a latex paint. Ray 2 also reported limited success in visualizing blood under painted surfaces 2. No attempt was made to scrape or separate the blood from the paint samples. Samples were subjected to Chelex™ DNA extraction and then amplified using Profiler Plus™. The authors reported that a full DNA profile was obtained from blood samples under paint. The authors also reported that blood could be detected under wallpaper using the Polilight™. From the photographs it appeared that the blood absorbed the ultraviolet light giving it a dark appearance. Blood was visible under three coats of paint. In their experiments it appears that blood was deposited directly on wood, plaster, brick, and metal and then painted over with various colors of light colored water based paint and white acrylic paint. Vandenberg and van Oorschot 1 reported on finding blood under paint using the Polilight™ PL500 at about 415nm. The investigators went to a local paint store where a fresh gallon of similar paint and color formula was obtained.Ī search of the forensic literature resulted in few references describing this type of research. To assist with this experiment the investigator was able to search the crime scene residence and recover the original paint buckets utilized for the paint on the walls at the time of the homicide. The author was asked to investigate the possibility of detecting blood under painted surfaces and recommend a method of searching for and detecting blood under these conditions. The suspect(s) were believed to have painted over the bloodstained walls in the crime scene shortly after the murder. In August of 2005 the author was contacted by an investigator with the State Attorney General’s office in Denver regarding a three year old homicide case. Experimental Detection of Blood Under Painted Surfaces
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